When a VM crashes with an active UART DMA transfer in progress, the
SMMU raises context faults as the DMA engine continues to access IOVAs
that are invalidated when the VM's memory context is torn down. These
faults can affect other VMs sharing the same SMMU instance and obscure
the root cause of the crash. Additionally, a stuck TX transfer on the
panic console UART can cause the panic handler to stall, dropping the
panic output.
Register a panic notifier to stop TX and RX. The notifier does not take
the port lock, since panic can be entered with the lock already held by
the interrupted context, and there is no safe way to detect that here;
instead, the device's runtime PM status is checked first so that TX/RX
are only stopped while the hardware is still clocked and accessible,
and the register accesses are skipped entirely once the device is
runtime suspended.
Signed-off-by: Praveen Talari <praveen.talari@oss.qualcomm.com>
Link: https://patch.msgid.link/20260715-add_shutdown_and_panic_notifier_serial-v1-2-23e3787c7109@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
During system reboot, an active UART DMA transfer can leave the GENI
Serial Engine in an indeterminate state. On VM-based platforms, if a
DMA transfer is in progress when the VM is shut down, the SMMU can
raise context faults as the DMA engine continues to access IOVAs that
have already been invalidated during VM teardown.
Add a shutdown callback to stop TX and RX and bring the hardware to
idle before the system resets, preventing both hardware state corruption
on reboot and SMMU faults during VM shutdown. The port lock is not taken
here since shutdown runs from process context with the device already
quiesced from the UART core's perspective; instead, the runtime PM status
is checked so that TX/RX are only stopped while clocks and resources are
still active, avoiding any register access once the device is runtime
suspended.
Signed-off-by: Praveen Talari <praveen.talari@oss.qualcomm.com>
Link: https://patch.msgid.link/20260715-add_shutdown_and_panic_notifier_serial-v1-1-23e3787c7109@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add tracing to the Qualcomm GENI serial driver to improve runtime
observability.
Trace hooks are added at key points including termios and clock
configuration, manual control get/set, interrupt handling, and data
TX/RX paths.
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Praveen Talari <praveen.talari@oss.qualcomm.com>
Link: https://patch.msgid.link/20260710-add-tracepoints-for-qcom-geni-serial-v6-2-2bb6b6836dfd@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Displaying "32be" is wrong for UPIO_MEM32. Fix and simplify by displaying
"32" for MEM32 and MEM32BE UPIO types.
Fixes: 86305190f3 ("serial: uniformize serial port I/O infos display")
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260716211216.2583291-1-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With CONFIG_SERIAL_8250_HUB6=m, we have the following compile error:
../drivers/tty/serial/8250/8250_hub6.c:46:6: error: redefinition of
'hub6_match_port'
Fix hub6_match_port() prototype definition by using IS_REACHABLE() to
support both built-in and module values, and substitute empty prototype
otherwise.
Fixes: 3d406299d8 ("serial: 8250_hub6: add hub6_match_port()")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202607150717.2YxVdWpX-lkp@intel.com/
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260715153707.4181828-1-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here are some small tty/serial/vt fixes for 7.2-rc3 that resolve some
reported problems. Included in here are:
- vt spurious modifier issue that showed up in -rc1 (reported a bunch)
- 8250 driver bugfixes
- msm serial driver bugfix
- max310x serial driver bugfix
All of these have been in linux-next with no reported issues
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-7.2-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial fixes from Greg KH:
"Here are some small tty/serial/vt fixes for 7.2-rc3 that resolve some
reported problems. Included in here are:
- vt spurious modifier issue that showed up in -rc1 (reported a
bunch)
- 8250 driver bugfixes
- msm serial driver bugfix
- max310x serial driver bugfix
All of these have been in linux-next with no reported issues"
* tag 'tty-7.2-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
serial: 8250: Ignore flow control on suspend/resume with no_console_suspend
serial: 8250_mid: Disable DMA for selected platforms
serial: 8250_omap: clear rx_running on zero-length DMA completes
vt: fix spurious modifier in CSI/cursor key sequences
serial: msm: Disable DMA for kernel console UART
serial: max310x: implement gpio_chip::get_direction()
Now that we have a new UPIO_BUS I/O type, use it to register our serial
port. This allows the driver to work properly when using DT where
membase/iobase are not set.
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260521-tty-upio-v3-10-bf74567994a0@dimonoff.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that we have a new UPIO_BUS I/O type, use it to register our serial
port and remove obscure membase/iobase workaround.
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260521-tty-upio-v3-9-bf74567994a0@dimonoff.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that we have a new UPIO_BUS I/O type, use it to register our serial
port and remove ambiguous membase/iobase workaround.
Note that commit 5da6b1c079 ("sc16is7xx: Set iobase to device index")
used the iobase field as an index within the device to allow infering
the order through sysfs, but this is no longer needed since
commit 1ef2c2df11 ("serial: core: Fix serial core controller port name
to show controller id").
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260521-tty-upio-v3-8-bf74567994a0@dimonoff.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
I2C/SPI serial drivers don't use the following struct uart_port variables:
port->membase
port->mapbase
port->iobase
However, they are forced to set membase to a non-zero value so that
uart_configure_port() will succeed because of the following check:
/* If there isn't a port here, don't do anything further. */
if (!port->iobase && !port->mapbase && !port->membase)
return;
Add a new I/O type for SPI and I2C bus devices to remove the need to
implement the kind of above-mentioned ambiguous workarounds to make them
work. Now that UART report functions are using uart_iotype_*() functions,
no more irrelevant I/O information are being printed for UPIO_BUS iotypes.
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260521-tty-upio-v3-7-bf74567994a0@dimonoff.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make use of new functions uart_iotype_mmio() and uart_iotype_legacy_io()
to simplify and improve code readability, as well as avoid some variables
init if the iotype is not valid.
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260521-tty-upio-v3-6-bf74567994a0@dimonoff.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make use of new functions uart_iotype_mmio() and uart_iotype_legacy_io()
to simplify and improve code readability.
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260521-tty-upio-v3-5-bf74567994a0@dimonoff.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Uniformize serial port I/O infos display from three different functions
that display mostly the same information, but with some variations, by
adding a common function.
This make use of new functions uart_iotype_mmio() and
uart_iotype_legacy_io() to simplify and improve code readability.
This will prevent displaying irrelevant information for future IO types
(ex: UPIO_BUS), while also addressing the (eventually) invalid check for
"iotype >= UPIO_MEM".
This also allows us to remove the confusing cast to (unsigned long long)
for iobase which is defined as an unsigned long, and use %pa to display the
mapbase pointer, as it is done in earlycon_print_info().
Replace snprintf with more robust scnprintf so we could perhaps one day get
rid of snprintf() entirely.
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260521-tty-upio-v3-4-bf74567994a0@dimonoff.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make use of new functions uart_iotype_mmio() and uart_iotype_legacy_io()
to simplify and improve code readability.
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260521-tty-upio-v3-3-bf74567994a0@dimonoff.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Move the entire hub6 related match port check into its own function in
8250_hub6.c and add a stub for the case when hub6 code is not even built
into kernel.
Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260521-tty-upio-v3-1-bf74567994a0@dimonoff.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If no_console_suspend is specified, on suspend the 8250 console driver
uses a scratch register (UART_SCR) to store a special canary value. This
is used during the resume path to identify a printk() call before the
driver's own ->resume() callback. In this case,
serial8250_console_restore() is called to quickly re-init the 8250 for
console printing.
See commit 4516d50aab ("serial: 8250: Use canary to restart console after
suspend") for the original motivation.
Unfortunately, this canary workaround does not work in all cases (such as
suspend to mem) because the scratch register will not reset. This has not
been a real issue until now because it could simply lead to some garbage
characters upon resume. However, with the introduction of console flow
control it becomes a real problem because a failed suspend/resume detection
when flow control is enabled leads to all characters hitting the flow
control timeout.
Workaround this issue by temporarily ignoring console flow control when
the debug canary suspend/resume detection is active.
Fixes: 5e6dfb87b1 ("serial: 8250: Add support for console flow control")
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://patch.msgid.link/20260707141032.5074-1-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In accordance with Errata (specification updates)
HSUART May Stop Functioning when DMA is Active.
- Denverton document #572409, rev 3.4, DNV60
- Ice Lake Xeon D document #714070, ICXD65
- Snowridge document #731931, SNR44
For a quick fix just disable the respective callbacks during the device probe.
Depending on the future development we might remove them completely.
Reported-by: micas-opensource <zjianan156@gmail.com>
Closes: https://lore.kernel.org/linux-serial/20250625031409.2404219-1-opensource@ruijie.com.cn/
Fixes: 6ede6dcd87 ("serial: 8250_mid: add support for DMA engine handling from UART MMIO")
Cc: stable <stable@kernel.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20260626094937.561776-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On AM33xx RX DMA only triggers when the FIFO reaches the
configured threshold (typically 48 bytes). For smaller bursts
no DMA request is issued and the FIFO is drained by RX timeout.
In this case __dma_rx_do_complete() can legitimately see count == 0.
The current code exits early in this case and does not clear
dma->rx_running, leaving the DMA state inconsistent. This can
prevent RX DMA from restarting and may cause
omap_8250_rx_dma_flush() to fail, marking DMA as broken.
Fix this by clearing dma->rx_running once the DMA transfer has
completed or been terminated, even if no data was transferred.
Fixes: a5fd8945a4 ("serial: 8250: 8250_omap.c: Clear DMA RX running status only after DMA termination is done")
Cc: stable <stable@kernel.org>
Signed-off-by: Matthias Feser <mfe@KBSgmbhfr.onmicrosoft.com>
Reviewed-by: Moteen Shah <m-shah@ti.com>
Link: https://patch.msgid.link/BE3P281MB55155F2F5795E411F5A65282EE0B2@BE3P281MB5515.DEUP281.PROD.OUTLOOK.COM
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
csi_modifier_param() builds the xterm modifier parameter from
shift_state, counting KG_SHIFTL/KG_SHIFTR as Shift, KG_ALTGR as Alt
and KG_CTRLL/KG_CTRLR as Ctrl in addition to the canonical KG_SHIFT,
KG_ALT and KG_CTRL.
That is wrong when those weights are not plain modifiers. Keymaps
derived from XKB layouts (by kbd's xkbsupport, and by the
console-setup used in Debian, Ubuntu and others) encode the active
layout group using KG_SHIFTL/KG_SHIFTR:
group 1: -
group 2: shiftl
group 3: shiftr
group 4: shiftl | shiftr
So while a non-default layout group is selected, KG_SHIFTL and/or
KG_SHIFTR are set in shift_state with no Shift key held.
csi_modifier_param() then adds a spurious Shift to every cursor and
CSI key: pressing Up while group 2 is active emits ESC[1;2A (Shift+Up)
instead of ESC[A. KG_ALTGR has the same problem since it is the
standard third-level selector.
Normal keymaps bind the physical Shift/Ctrl/Alt keys to KG_SHIFT,
KG_CTRL and KG_ALT, leaving the left/right and AltGr weights free for
layout and level selection. Count only those canonical weights, so
genuine modifiers are still encoded while layout/level selectors are
not.
Fixes: 4af70f1516 ("vt: add modifier support to cursor keys")
Reported-by: Alexey Gladkov <legion@kernel.org>
Closes: https://lore.kernel.org/kbd/aj2gR0Y7sM6i9s2G@example.org/
Cc: stable <stable@kernel.org>
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Link: https://patch.msgid.link/20260626024833.3419086-1-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver currently relies on qcom_geni_serial_pm() through the
uart_ops.pm callback to manage runtime PM references. However, the
callback has a void return type, so failures from
pm_runtime_resume_and_get() cannot be propagated to the caller.
As a result, startup() may continue and access hardware even when the
runtime PM resume operation failed, leading to register accesses while
the device is not powered.
Move runtime PM acquisition to qcom_geni_serial_startup() and release it
to qcom_geni_serial_shutdown(). Since startup() can return an error, PM
resume failures are now detected and propagated before any hardware
initialization is performed. The startup/shutdown pair also provides a
natural place to balance runtime PM references for normal port usage.
During probe, uart_add_one_port() may configure the port before any user
opens the TTY, meaning startup() has not yet been called. To keep the
hardware powered during port registration, wrap uart_add_one_port() with
PM_RUNTIME_ACQUIRE_IF_ENABLED() and PM_RUNTIME_ACQUIRE_ERR(). This
ensures the device is resumed for the duration of registration and that
the runtime PM reference is automatically released afterwards.
By moving runtime PM handling out of uart_ops.pm, resume failures are no
longer silently ignored and all hardware accesses are guaranteed to
occur while the device is powered.
Signed-off-by: Praveen Talari <praveen.talari@oss.qualcomm.com>
Link: https://patch.msgid.link/20260710-remove_uart_change_state-v1-1-8e8468da22a1@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Unlike modern SoCs that just work in both big-endian and little-endian
mode using the readl()/writel() or readb()/writeb() accessors, the
internal registers on ixp4xx behave like native-endian 32-bit registers
in both modes, which requires adjusting the register address
when using 8-bit access.
The existing dts files are written for big-endian kernels and 8-bit
access, which does not work with little-endian kernels.
Add a quirk that makes the 8250 OF driver:
1. Mask off any hardcoded offset.
2. Add the += 3 offset if and only if we are running on big endian.
This should work in all combinations of big-endian and little-endian
kernels with either variant of the DTS file.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[linusw@kernel.org: Modified to just play with the offset]
Signed-off-by: Linus Walleij <linusw@kernel.org>
Link: https://patch.msgid.link/20260709-ixp4xx-serial-hackfix-v2-1-465fc8e4c54c@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The qcom GENI serial DMA TX completion path advances the transmit fifo by
the number of bytes recorded in port->tx_remaining.
If uart_flush_buffer() runs after the hardware has completed a DMA
transfer but before the DMA completion interrupt has been handled, the
serial core resets the transmit fifo while port->tx_remaining still
describes the old DMA transfer.
A previous fix avoided advancing an empty fifo by checking that the fifo
length is at least tx_remaining. That still does not distinguish the old
DMA payload from new bytes written after the flush. If userspace writes
new data before the stale DMA completion interrupt is handled, the fifo
can again contain at least tx_remaining bytes and the stale completion
can advance and discard those new bytes.
Mark an in-flight DMA transfer stale when the transmit fifo is flushed.
The later completion still unprepares the original DMA mapping using the
saved length, but it no longer advances the transmit fifo.
Fixes: 2aaa43c707 ("tty: serial: qcom-geni-serial: add support for serial engine DMA")
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
Link: https://patch.msgid.link/20260708131726.768692-1-lgs201920130244@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
During system power-off, systemd closes the console UART and blocks in
tty_wait_until_sent() waiting for pending TX completion before
uart_shutdown() can cancel pending TX operations. With the default
closing_wait of 30s, this causes a watchdog reset when systemd is
responsible for watchdog feeding.
Set closing_wait to ASYNC_CLOSING_WAIT_NONE in startup() for console
ports to bypass tty_wait_until_sent() on close, allowing uart_shutdown()
to cancel TX commands cleanly. This change doesn't impact regular ports
functionality.
Signed-off-by: Aniket Randive <aniket.randive@oss.qualcomm.com>
Link: https://patch.msgid.link/20260706093749.836121-1-aniket.randive@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
During system sleep the hardware resources (clocks, interconnect) are
not gated because the runtime-suspend callback is never invoked from
the system sleep path. This prevents the platform from reaching its
lowest idle state.
The system sleep callbacks qcom_geni_serial_suspend() and
qcom_geni_serial_resume() rely solely on uart_suspend_port() /
uart_resume_port() to manage power. uart_suspend_port() drives the
UART PM state machine to UART_PM_STATE_OFF, which in turn calls
pm_runtime_put_sync() and eventually the runtime-suspend callback.
However, if the runtime-PM usage count is still elevated at the time
of system sleep (e.g. the port is held active by an open file
descriptor), the runtime-suspend callback is never invoked and the
hardware resources (clocks, interconnect) remain enabled across
suspend, preventing the platform from reaching its lowest idle state.
Fix this by calling pm_runtime_force_suspend() at the end of
qcom_geni_serial_suspend() so that the runtime-suspend callback is
always executed regardless of the usage count, and by calling
pm_runtime_force_resume() at the start of qcom_geni_serial_resume()
to restore those resources before uart_resume_port() re-opens the
port.
Signed-off-by: Praveen Talari <praveen.talari@oss.qualcomm.com>
Link: https://patch.msgid.link/20260702-add_force_suspend_resume_to_system_sleep_callbacks-v2-1-b79e254a7015@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
geni_se_rx_dma_prep() calls dma_map_single() which can trigger IOMMU
page table allocations under GFP_KERNEL. This is unsafe when called
from qcom_geni_serial_start_rx_dma(), which runs in atomic context
producing a "sleeping function called from invalid context" splat:
__might_resched+0x15c/0x17c
__alloc_pages_noprof+0xe4/0x4c8
qcom_io_pgtable_alloc_page+0x100/0x250
__arm_lpae_map+0x2d0/0x870
geni_se_rx_dma_prep+0xd8/0x158
qcom_geni_serial_start_rx_dma+0x84/0x16c
qcom_geni_serial_startup+0x70/0x104
Fix this by mapping the RX DMA buffer once during probe, where sleeping
is allowed, and keeping it mapped for the lifetime of the device.
Replace the geni_se_rx_dma_prep() / geni_se_rx_dma_unprep() calls in
the runtime paths with dma_sync_single_for_device() before initiating a
transfer and dma_sync_single_for_cpu() on completion, using the persistent
mapping. The buffer is unmapped in probe's error path and in remove().
Signed-off-by: Praveen Talari <praveen.talari@oss.qualcomm.com>
Link: https://patch.msgid.link/20260701-fix-sleep-in-atomic-context-during-rx-dma-setup-v1-1-95c208380c65@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ma35d1serial_console_init_port() stores matching UART device nodes in
ma35d1serial_uart_nodes[] with an extra of_node_get() so that console
setup can later read the "reg" property. However, the stored references
are never released after console setup has finished using them.
Drop the stored node reference after ma35d1serial_console_setup() reads
the "reg" property, and clear the array slot to avoid leaving a stale
pointer behind. Also release the iterator reference before breaking out
of for_each_matching_node(), since the normal iterator advance will not
run in that path.
Fixes: 930cbf92db ("tty: serial: Add Nuvoton ma35d1 serial driver support")
Signed-off-by: Yuho Choi <dbgh9129@gmail.com>
Link: https://patch.msgid.link/20260630214043.1887351-1-dbgh9129@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
While being less compact, using named initializers allows to more easily
see which members of the structs are assigned which value without having
to lookup the declaration of the struct. And it's also more robust
against changes to the struct definition.
The mentioned robustness is relevant for a planned change to struct
pnp_device_id that replaces .driver_data by an anonymous union.
This patch doesn't modify the compiled array, only their representation
in source form benefits. The former was confirmed with x86 and arm64
builds.
Also simplify the list terminator and use a consistent and more common
indention.
Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
Link: https://patch.msgid.link/20260629170409.3412413-2-u.kleine-koenig@baylibre.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We do unneeded "double free" (emptying an empty list) in one case.
This is not a critical issue at all, the fix just makes code robust
against any possible future changes in the flow.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20260617092515.2649521-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Replacing strcpy() with strscpy() ensures that overflow of the target
buffer cannot happen.
Signed-off-by: David Laight <david.laight.linux@gmail.com>
Reviewed-by: Daniel Thompson (RISCstar) <danielt@kernel.org>
Link: https://patch.msgid.link/20260608095523.2606-10-david.laight.linux@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add check for pci_get_slot() to prevent a potetial
null pointer dereference in pch_request_dma().
Signed-off-by: Haoxiang Li <haoxiang_li2024@163.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20260623140539.2272473-1-haoxiang_li2024@163.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On x86_64 defconfig, booting with driver_async_probe=serial hangs in early
init. The 8250 PNP driver is put onto the async probe pool.
serial8250_register_8250_port() runs in a kworker concurrently with the
ISA registration done from the serial8250_init() initcall resulting in a
deadlock or NULL dereference.
- Deadlock: serial_core_register_port() holds port_mutex across
serial_core_add_one_port()
uart_configure_port()
autoconfig_irq()
probe_irq_on()
async_synchronize_full(),
which waits for the async probe pool to drain.
The async PNP worker reaches the "port already in use" check and
tries to unregister it.
serial8250_register_8250_port()
uart_remove_one_port()
serial_core_unregister_port()
This blocks on port_mutex.
The init thread waits for the worker and the worker waits for the
init thread.
- NULL deref: when the worker instead observes a slot whose port.dev
is set but whose port_dev has not yet been populated, it hits the
null pointer on the call to serial_core_get_ctrl_dev() in
serial_core_unregister_port().
Signed-off-by: Rahul Bukte <rahul.bukte@sony.com>
Link: https://patch.msgid.link/20260610054130.2825182-1-rahul.bukte@sony.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
platform_get_irq is a newer API for this that does not require
irq_dispose_mapping().
Assisted-by: opencode:big-pickle
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Link: https://patch.msgid.link/20260607021117.6325-1-rosenp@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When two PnP devices map to the same physical port, the serial8250 driver
removes and re-registers the console structure for the same port.
During re-registration, the console structure still has CON_PRINTBUFFER set
from the initial registration, which causes console_init_seq() to set
console->seq to syslog_seq. This results in re-printing the entire
system log buffer, which may lead to RCU stall on slow serial consoles.
Clear CON_PRINTBUFFER when re-registering a port to prevent duplicate
log printing.
Fixes: 835d844d1a ("8250_pnp: do pnp probe before legacy probe")
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Fushuai Wang <wangfushuai@baidu.com>
Link: https://patch.msgid.link/20260522101042.21976-1-fushuai.wang@linux.dev
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
psc_num is derived from port->mapbase bits 11:8, giving a range of
0-15, but the psc_mclk_clk and psc_ipg_clk arrays are sized to
MPC52xx_PSC_MAXNUM (12 when CONFIG_PPC_MPC512x is set). A malformed
device tree with bits 11:8 >= 12 would cause out-of-bounds writes
in mpc512x_psc_alloc_clock() and out-of-bounds reads/writes in
mpc512x_psc_relse_clock() and mpc512x_psc_endis_clock(). The same
unchecked index also appears in mpc512x_psc_handle_irq().
Add ARRAY_SIZE() bounds checks to all four functions before using
psc_num as an array index.
Assisted-by: Opencode:big-pickle
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Link: https://patch.msgid.link/20260530061025.11625-1-rosenp@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
At the moment, concurrent writes from userspace and the kernel to the
console can trigger a race condition that results in an infinite loop of
the same messages printed over and over again. This is most likely to
happen during system startup or shutdown when the init system starts/stops
a large number of system services that interact with various kernel code.
When userspace writes to the TTY device, the driver initiates an
asynchronous DMA transfer and releases the port lock. At the same moment,
the kernel printk path might grab the port lock and re-configure the UART
controller for PIO, without waiting for the DMA operation to complete. It
seems like this collision results in zero progress being reported for the
DMA engine, so the same text is printed to the console over and over again.
For the kernel console, we want a reliable output path that will be
functional even during crashes etc. So rather than implementing complex
code to synchronize the kernel console write routines with the userspace
DMA write routines, simply disable DMA for the console UART instance.
Similar checks exist in many other serial drivers, e.g. 8250_port.c,
imx.c, sh-sci.c etc.
Cc: stable <stable@kernel.org>
Fixes: 3a878c430f ("tty: serial: msm: Add TX DMA support")
Signed-off-by: Stephan Gerhold <stephan.gerhold@linaro.org>
Acked-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Link: https://patch.msgid.link/20260706-serial-msm-console-dma-collision-v1-1-3179b8cb1d89@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It's strongly recommended for GPIO drivers to always implement the
.get_direction() callback - even when the direction is tracked in
software. The GPIO core emits a warning when the callback is missing
and a user reads the direction of a line, e.g. via
/sys/kernel/debug/gpio.
The MAX310X keeps the GPIO direction in the GPIOCFG register (a set bit
selects output), which the existing direction_input/output callbacks
already program, so the current direction can be read back directly.
Fixes: f65444187a ("serial: New serial driver MAX310X")
Cc: stable <stable@kernel.org>
Signed-off-by: Tapio Reijonen <tapio.reijonen@vaisala.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Reviewed-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260615-b4-serial-max310x-gpio-get-direction-v2-1-4704ba2b181a@vaisala.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
guard()s express more clearly what the lock protects and let the
function return immediately instead of jumping to an unlock label.
Signed-off-by: John de la Garza <john@jjdev.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://patch.msgid.link/20260701231215.4092457-1-john@jjdev.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Convert the manual spin_lock_irq()/rcu_read_lock() nesting in tiocspgrp()
to scoped guard()s. This drops the out_unlock and out_unlock_ctrl labels
and lets the error paths return directly.
No functional change intended.
Signed-off-by: John de la Garza <john@jjdev.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://patch.msgid.link/20260701030139.3189030-1-john@jjdev.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The MAX310x DT binding pulls in /schemas/serial/rs485.yaml via its allOf
list, advertising the rs485-* properties defined there - none of which
were honoured at runtime, because the driver never called
uart_get_rs485_mode().
All channels share the parent SPI/I2C device, so uart_get_rs485_mode()
called directly on each port would read the same chip-level fwnode for
every call. Walk dev->of_node's children for the "serial@N" subnode
with matching reg, and temporarily retarget the parent device's fwnode
while uart_get_rs485_mode() runs, so each channel picks up its own
subnode's properties. Probe is serialised, so the swap is safe.
For single-channel variants (max3107, max3108), fall back to the chip's
own fwnode when no subnode is present, so existing DTs that declare
rs485 properties at the top level keep working.
Signed-off-by: Tapio Reijonen <tapio.reijonen@vaisala.com>
Link: https://patch.msgid.link/20260615-b4-max310x-rs485-dt-v3-3-7e79f064bdd7@vaisala.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The MAX310x exposes four GPIOs per UART port via an in-driver
gpio_chip. devm_gpiochip_add_data() used to run after the per-port
uart_add_one_port() loop, so a device-tree consumer referencing one of
the chip's own GPIOs (for example rs485-term-gpios = <&max310x 0 ...>)
could not resolve it during port registration: the GPIO provider it
waits for is the very driver still trying to register, and the lookup
returns -EPROBE_DEFER on its own provider, deferring probe forever.
Split the per-port setup into two passes around the gpio_chip
registration:
1. Initialise per-port state - port struct fields, regmap binding,
IRQ disable, work queues. The gpio_chip callbacks dereference
s->p[i].regmap via to_max310x_port() and become callable as soon
as the chip is visible to gpiolib, so every entry must be
populated first.
2. devm_gpiochip_add_data() - register the gpio_chip.
3. Allocate a line, uart_add_one_port(), set_bit(), max310x_power().
Keeping line allocation, registration and set_bit() together
preserves the existing "bit set <=> port registered" rollback
invariant that out_uart relies on.
Signed-off-by: Tapio Reijonen <tapio.reijonen@vaisala.com>
Link: https://patch.msgid.link/20260615-b4-max310x-rs485-dt-v3-1-7e79f064bdd7@vaisala.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
men_z135_probe() allocates a receive staging buffer filled by the
CPU via memcpy_fromio() from the device MMIO region.
This buffer can be allocated with kmalloc() as there's nothing special
about it to go directly to the page allocator.
kmalloc() provides a better API that does not require ugly casts and
kfree() does not need to know the size of the freed object.
Replace use of __get_free_page() with kmalloc() and free_page() with
kfree().
Link: https://lore.kernel.org/all/635405e4-9423-4a25-a6e7-e03c8ea0bcbe@redhat.com
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Link: https://patch.msgid.link/20260528-b4-tty-v1-3-9da9f7aec5f2@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
rs_startup() allocates a transmit ring buffer that is used to buffer reads
and writes from/to serial data register.
This buffer can be allocated with kmalloc() as there's nothing special
about it to go directly to the page allocator.
kmalloc() provides a better API that does not require ugly casts and
kfree() does not need to know the size of the freed object.
Replace use of get_zeroed_page() with kzalloc() and free_page() with
kfree().
Link: https://lore.kernel.org/all/635405e4-9423-4a25-a6e7-e03c8ea0bcbe@redhat.com
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Link: https://patch.msgid.link/20260528-b4-tty-v1-2-9da9f7aec5f2@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pch_uart_init_port() allocates a staging buffer for non-DMA receive path
using __get_free_page().
This buffer can be allocated with kmalloc() as there's nothing special
about it to go directly to the page allocator.
kmalloc() provides a better API that does not require ugly casts and
kfree() does not need to know the size of the freed object.
Replace use of __get_free_page() with kmalloc() and free_page() with
kfree().
Link: https://lore.kernel.org/all/635405e4-9423-4a25-a6e7-e03c8ea0bcbe@redhat.com
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Link: https://patch.msgid.link/20260528-b4-tty-v1-1-9da9f7aec5f2@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The .driver_data member of the struct pci_device_id array were
initialized by list expressions relying on hidden assignment of .class
and .class_mask in PCI_VDEVICE().
Make the initialization more robust by using a named initializer. This
robustness is relevant for a planned change to struct pci_device_id that
replaces .driver_data by an anonymous union.
This change doesn't introduce changes to the compiled pci_device_id
array. Tested on x86 and arm64.
Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
Link: https://patch.msgid.link/20260524131905.871222-2-u.kleine-koenig@baylibre.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The .driver_data member of the struct pci_device_id array were
initialized by list expressions. This isn't easily readable if you're
not into PCI, still more given that it's hidden in macros. Using named
initializers is more explicit and thus easier to parse for a human. And
it's also more robust against changes to the struct definition.
The mentioned robustness is relevant for a planned change to struct
pci_device_id that replaces .driver_data by an anonymous union.
Also drop a few explicit zeros that are not needed and improve
indention.
This change doesn't introduce changes to the compiled pci_device_id
array. Tested on x86 and arm64.
Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
Link: https://patch.msgid.link/20260522140103.769262-2-u.kleine-koenig@baylibre.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Using guard()s is cleaner and safer.
goldfish_tty_probe() is omitted due to the crossing err_unmap
goto-label. Using scoped_guard() does not look that nice there. Perhaps
if someone refactored the locked part into a separate function...
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://patch.msgid.link/20260703084717.176442-4-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty/goldfish.c is the only user of gf_write_ptr(). Move it there, drop
the unneeded casts, and name it appropriately.
FTR, the last non-tty user was removed in 2018 by 4ae0fe70a0 ("Delete
the goldfish_nand driver.").
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://patch.msgid.link/20260703084717.176442-3-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Replace the #include of <linux/mod_devicetable.h> by the more specific
<linux/device-id/*.h> where applicable. For most cases the include
can be dropped completely, only a few drivers need one or two headers
added.
Acked-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/1a3f2007c5c5dcf555c09a4035ce3ae8ef1b6c49.1782808461.git.u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
Here is the big set of TTY and Serial driver updates for 7.2-rc1.
Overall we end up removing more code than added, due to an obsolete
synclink_gt driver being removed from the tree, always a nice thing to
see happen.
Other than that driver removal, major things included in here are:
- max310x serial driver updates and fixes
- 8250 driver updates and rework in places to make it more "modern"
- dts file updates
- serial driver core tweaks and updates
- vt code cleanups
- vc_screen crash fixes
- other minor driver updates and cleanups
All of these have been in linux-next for well over a week with no
reported issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-7.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty / serial driver updates from Greg KH:
"Here is the big set of TTY and Serial driver updates for 7.2-rc1.
Overall we end up removing more code than added, due to an obsolete
synclink_gt driver being removed from the tree, always a nice thing to
see happen.
Other than that driver removal, major things included in here are:
- max310x serial driver updates and fixes
- 8250 driver updates and rework in places to make it more "modern"
- dts file updates
- serial driver core tweaks and updates
- vt code cleanups
- vc_screen crash fixes
- other minor driver updates and cleanups
All of these have been in linux-next for well over a week with no
reported issues"
* tag 'tty-7.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (49 commits)
serial: 8250_pci: Don't specify conflicting values to pci_device_id members
vc_screen: fix null-ptr-deref in vcs_notifier() during concurrent vcs_write
serial: qcom_geni: Fix RX DMA stall when SE_DMA_RX_LEN_IN is zero
vt: merge ucs_is_zero_width()/ucs_is_double_width() into ucs_get_width()
serial: 8250: fix possible ISR soft lockup
dt-bindings: serial: rs485: remove deprecated .txt binding stub
serial: qcom-geni: trace: Add tracepoint support for Qualcomm GENI serial
tty: serial: Use named initializers for arrays of i2c_device_data
serial: 8250_dw: remove clock-notifier infrastructure
serial: 8250_dw: unregister 8250 port if clk_notifier_register() fails
amba/serial: amba-pl011: Bring back zx29 UART support
serial: 8250: Add support for console flow control
serial: 8250: Check LSR timeout on console flow control
serial: 8250: Set cons_flow on port registration
tty: serial: 8250: protect against NULL uart->port.dev in register
arm64: dts: add support for A9 based Amlogic BY401
dt-bindings: arm: amlogic: add A311Y3 support
serial: max310x: fix compile errors if CONFIG_SPI_MASTER is disabled
serial: qcom-geni: Avoid probing debug console UART without console support
serial: max310x: add comments for PLL limits
...
Removal of drivers:
- Hercules monochrome ISA graphics adapter driver [Ethan Nelson-Moore]
- Hercules mdacon console driver [Ethan Nelson-Moore]
Changes affecting many drivers at once:
- possible memory leak fixes in various drivers [Abdun Nihaal]
- many conversions to use strscpy() [David Laight]
- Use named initializers in drivers [Uwe Kleine-König]
Code fixes:
- fbcon: don't suspend/resume when vc is graphics mode [Lu Yao]
- modedb: fix a possible UAF in fb_find_mode() [Tuo Li]
- modedb: Fix entry for 1920x1080-60 mode [Steffen Persvold]
- arm: Export acorndata_8x8 font symbol for bootloader [Helge Deller]
- omap2: fix use-after-free in omapfb_mmap [Hongling Zeng]
Cleanups:
- pxa168fb: use devm_ioremap_resource() [AlbertoArostegui]
- provice helpers for fb_set_var() and fb_blank() and fbcon updates [Thomas Zimmermann]
- fbcon: Use correct type for vc_resize() return value [Jiacheng Yu]
- chipsfb: add missing MODULE_DESCRIPTION() macro [Rahman Mahmutović]
- sunxvr2500: replace printk with device-aware logging functions [Rahman Mahmutović]
- sm712: Fix operator precedence in big_swap macro [Li RongQing]
- imxfb: Use of_device_get_match_data() [Rosen Penev]
- atmel_lcdfb: Use of_device_get_match_data() [Rosen Penev]
Documentation fixes:
- grvga: Fix CLUT register address offset in comment [Eduardo Silva]
- omap/dss: Fix stale modedb.c path [Costa Shulyupin]
- correct CONFIG_FB_TILEBLITTING macro name in #endif comment [Ethan Nelson-Moore]
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Merge tag 'fbdev-for-7.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev
Pull fbdev updates from Helge Deller:
"Beside the removal of the Hercules monochrome ISA graphics driver and
the corresponding text console driver, there is just the typical
maintanance with smaller driver fixes and cleanups:
Removal of drivers:
- Hercules monochrome ISA graphics adapter driver (Ethan Nelson-Moore)
- Hercules mdacon console driver (Ethan Nelson-Moore)
Changes affecting many drivers at once:
- possible memory leak fixes in various drivers (Abdun Nihaal)
- many conversions to use strscpy() (David Laight)
- Use named initializers in drivers (Uwe Kleine-König)
Code fixes:
- fbcon: don't suspend/resume when vc is graphics mode (Lu Yao)
- modedb: fix a possible UAF in fb_find_mode() (Tuo Li)
- modedb: Fix entry for 1920x1080-60 mode (Steffen Persvold)
- arm: Export acorndata_8x8 font symbol for bootloader (Helge Deller)
- omap2: fix use-after-free in omapfb_mmap (Hongling Zeng)
Cleanups:
- pxa168fb: use devm_ioremap_resource() (Alberto Arostegui)
- provice helpers for fb_set_var() and fb_blank() and fbcon updates
(Thomas Zimmermann)
- fbcon: Use correct type for vc_resize() return value (Jiacheng Yu)
- chipsfb: add missing MODULE_DESCRIPTION() macro (Rahman Mahmutović)
- sunxvr2500: replace printk with device-aware logging functions
(Rahman Mahmutović)
- sm712: Fix operator precedence in big_swap macro (Li RongQing)
- imxfb: Use of_device_get_match_data() (Rosen Penev)
- atmel_lcdfb: Use of_device_get_match_data() (Rosen Penev)
Documentation fixes:
- grvga: Fix CLUT register address offset in comment (Eduardo Silva)
- omap/dss: Fix stale modedb.c path (Costa Shulyupin)
- correct CONFIG_FB_TILEBLITTING macro name in #endif comment (Ethan
Nelson-Moore)"
* tag 'fbdev-for-7.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev: (43 commits)
fbdev: modedb: Fix misaligned fields in the 1920x1080-60 mode
fbdev: modedb: fix a possible UAF in fb_find_mode()
fbdev: s3fb: Use strscpy() to copy strings into arrays
fbdev: sm501fb: Fix buffer errors in OF binding code
fbcon: correct CONFIG_FB_TILEBLITTING macro name in #endif comment
fbdev/arm: Export acorndata_8x8 font symbol for bootloader
fbdev: mmpfb: Use strscpy() to copy device name
fbdev: sisfb: Replace strlen() strcpy() pair with strscpy()
fbdev: rivafb: Use strscpy() to copy device name
fbdev: cyber2000fb: Use strscpy() to copy device name
fbdev: atmel_lcdfb: Use strscpy() to copy device name
fbdev: Do not export fbcon from fbdev
fbdev: Wrap fbcon updates from vga-switcheroo in helper
fbdev: Wrap user-invoked calls to fb_blank() in helper
fbdev: Wrap user-invoked calls to fb_set_var() in helper
fbdev: omap2: fix use-after-free in omapfb_mmap
docs: omap/dss: Fix stale modedb.c path
fbdev: pxa168fb: use devm_ioremap_resource() for MMIO
fbdev: grvga: Fix CLUT register address offset in comment
fbdev: sunxvr2500: replace printk with device-aware logging functions
...
- Use CIO device online variable instead of the internal FSM state to
determine device availability during purge operations
- Remove extra check of task_stack_page() because try_get_task_stack()
already takes care of that when reading /proc/<pid>/wchan
- Allow user-space to use the new SCLP action qualifier 4 for to
provide NVMe SMART log data to the platform.
- Send AP CHANGE uevents on successful bind and successful association
to notify user-space about SE operations on AP queue devices
- Add an s390dbf kernel parameter to configure debug log levels and
area sizes during early boot
- On arm64 the empty zero page is going to be mapped read-only.
Do the same for s390 with an explicit set_memory_ro() call
- Improve s390-specific bcr_serialize() and cpu_relax() implementations
- Remove all unused variables to avoid allmodconfig W=1 build fails
with latest clang-23
- Cleanup default Kconfig values for s390 selftests
- Add a s390-tod trace clock to allow comparing trace timestamps
between different systems or virtual machines on s390
- Remove the s390 implementation of strlcat() in favor of the
generic variant
- Make consistent the calling order between page_table_check_pte_clear()
and secure page conversion across all code paths
- Rearrange some fields within AP and zcrypt structs to reduce
memory consumption and unused holes
- Shorten GR_NUM and VX_NUM macros and move them to a separate header
- Replace __get_free_page() with kmalloc() in few sources
- Introduce an infrastructure for more efficient this_cpu operations.
Eliminate conditional branches when PREEMPT_NONE is removed
- Enable Rust support
- Use z10 as minimum architecture level, similar to the boot code,
to enforce a defined architecture level set
- Improve and convert various mem*() helper functions to C. For that
add .noinstr.text section to avoid orphaned warnings from the linker
- Fix the function pointer type in __ret_from_fork() to correct
the indirect call to match kernel thread return type of int
- Revert support for DCACHE_WORD_ACCESS to avoid an endless exception
loop on read from donated Ultravisor pages at unaligned addresses
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Merge tag 's390-7.2-1' of gitolite.kernel.org:pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Alexander Gordeev:
- Use CIO device online variable instead of the internal FSM state to
determine device availability during purge operations
- Remove extra check of task_stack_page() because try_get_task_stack()
already takes care of that when reading /proc/<pid>/wchan
- Allow user-space to use the new SCLP action qualifier 4 for to
provide NVMe SMART log data to the platform.
- Send AP CHANGE uevents on successful bind and successful association
to notify user-space about SE operations on AP queue devices
- Add an s390dbf kernel parameter to configure debug log levels and
area sizes during early boot
- On arm64 the empty zero page is going to be mapped read-only. Do the
same for s390 with an explicit set_memory_ro() call
- Improve s390-specific bcr_serialize() and cpu_relax() implementations
- Remove all unused variables to avoid allmodconfig W=1 build fails
with latest clang-23
- Cleanup default Kconfig values for s390 selftests
- Add a s390-tod trace clock to allow comparing trace timestamps
between different systems or virtual machines on s390
- Remove the s390 implementation of strlcat() in favor of the generic
variant
- Make consistent the calling order between
page_table_check_pte_clear() and secure page conversion across all
code paths
- Rearrange some fields within AP and zcrypt structs to reduce memory
consumption and unused holes
- Shorten GR_NUM and VX_NUM macros and move them to a separate header
- Replace __get_free_page() with kmalloc() in few sources
- Introduce an infrastructure for more efficient this_cpu operations.
Eliminate conditional branches when PREEMPT_NONE is removed
- Enable Rust support
- Use z10 as minimum architecture level, similar to the boot code, to
enforce a defined architecture level set
- Improve and convert various mem*() helper functions to C. For that
add .noinstr.text section to avoid orphaned warnings from the linker
- Fix the function pointer type in __ret_from_fork() to correct the
indirect call to match kernel thread return type of int
- Revert support for DCACHE_WORD_ACCESS to avoid an endless exception
loop on read from donated Ultravisor pages at unaligned addresses
* tag 's390-7.2-1' of gitolite.kernel.org:pub/scm/linux/kernel/git/s390/linux: (52 commits)
s390: Revert support for DCACHE_WORD_ACCESS
s390/process: Fix kernel thread function pointer type
s390/tishift: Convert __ashlti3(), __ashrti3(), __lshrti3() to C
s390/memmove: Optimize backward copy case
s390/string: Convert memset(16|32|64)() to C
s390/string: Convert memcpy() to C
s390/string: Convert memset() to C
s390/string: Convert memmove() to C
s390/string: Add -ffreestanding compile option to string.o
s390: Add .noinstr.text to boot and purgatory linker scripts
s390/purgatory: Enforce z10 minimum architecture level
s390: Enable Rust support
s390/cmpxchg: Fix KASAN stack-out-of-bounds in atomic helpers
rust: helpers: Add memchr wrapper for string operations
rust/bindgen_parameters: Mark s390 types as opaque to prevent repr conflicts
s390/jump_label: Implement ARCH_STATIC_BRANCH_JUMP_ASM and ARCH_STATIC_BRANCH_ASM macros
s390/bug: Provide ARCH_WARN_ASM for Rust WARN/BUG support
s390/ap: Fix locking issue in SE bind and associate sysfs functions
s390/percpu: Provide arch_this_cpu_write() implementation
s390/percpu: Provide arch_this_cpu_read() implementation
...
- deferred probe:
- Fix race where deferred probe timeout work could be permanently
canceled by using mod_delayed_work()
- Fix missing jiffies conversion in deferred_probe_extend_timeout()
- Guard timeout extension with delayed_work_pending() to prevent
premature firing
- Use system_percpu_wq instead of the deprecated system_wq
- Update deferred_probe_timeout documentation
- device:
- Replace direct struct device bitfield access (can_match, dma_iommu,
dma_skip_sync, dma_ops_bypass, state_synced, dma_coherent,
of_node_reused, offline, offline_disabled) with flag-based
accessors using bit operations
- Reject devices with unregistered buses
- Delete unused DEVICE_ATTR_PREALLOC()
- Add low-level device attribute macros with const show/store
callbacks, allowing device attributes to reside in read-only memory
- Move core device attributes to read-only memory
- Constify group array pointers in driver_add_groups() /
driver_remove_groups(), struct bus_type, and struct device_driver
- device property:
- Fix fwnode reference leak in fwnode_graph_get_endpoint_by_id()
- Initialize all fields of fwnode_handle in fwnode_init()
- Provide swnode_get()/swnode_put() wrappers around kobject_get/put()
- Allow passing struct software_node_ref_args pointers directly to
PROPERTY_ENTRY_REF()
- driver_override:
- Migrate amba, cdx, vmbus, and rpmsg to the generic driver_override
infrastructure, fixing a UAF from unsynchronized access to
driver_override in bus match() callbacks
- Remove the now-unused driver_set_override()
- firmware loader:
- Fix recursive lock deadlock in device_cache_fw_images() when async
work falls back to synchronous execution
- Fix device reference leak in firmware_upload_register()
- platform:
- Pass KBUILD_MODNAME through the platform driver registration macro
to create module symlinks in sysfs for built-in drivers; move
module_kset initialization to a pure_initcall and tegra cbb
registration to core_initcall to ensure correct ordering
- Pass THIS_MODULE implicitly through a coresight_init_driver() macro
- sysfs:
- Upgrade OOB write detection in sysfs_kf_seq_show() from printk to
WARN
- Add return value clamping to sysfs_kf_read()
- Rust:
- ACPI:
- Fix missing match data for PRP0001 by exporting
acpi_of_match_device()
- Auxiliary:
- Replace drvdata() with dedicated registration data on
auxiliary_device. drvdata() exposed the driver's bus device
private data beyond the driver's own scope, creating ordering
constraints and forcing the data to outlive all registrations
that access it. Registration data is instead scoped structurally
to the Registration object, making lifecycle ordering enforced
by construction rather than convention.
- Rust-native device driver lifetimes (HRT):
- Allow Rust device drivers to carry a lifetime parameter on their
bus device private data, tied to the device binding scope -- the
interval during which a bus device is bound to a driver. Device
resources like pci::Bar<'a> and IoMem<'a> can be stored directly
in the driver's bus device private data with a lifetime bounded
by the binding scope, so the compiler enforces at build time that
they do not outlive the binding. This removes Devres indirection
from every access site and eliminates try_access() failure paths
in destructors.
Bus driver traits use a Generic Associated Type (GAT)
Data<'bound> to introduce the lifetime on the private data,
rather than parameterizing the Driver trait itself. Auxiliary
registration data, where the lifetime is not introduced by a
trait callback but must be threaded through Registration, uses
the ForLt trait (a type-level abstraction for types generic over
a lifetime).
- Misc:
- Fix DT overlayed devices not probing by reverting the broken
treewide overlay fix and re-running fw_devlink consumer pickup when
an overlay is applied to a bound device
- Use root_device_register() for faux bus root device; add sanity
check for failed bus init
- Fix dev_has_sync_state() data race with READ_ONCE() and move it to
base.h
- Avoid spurious device_links warning when removing a device while
its supplier is unbinding
- Switch ISA bus to dynamic root device
- Fix suspicious RCU usage in kernfs_put()
- Remove devcoredump exit callback
- Constify devfreq_event_class
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Merge tag 'driver-core-7.2-rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/driver-core/driver-core
Pull driver core updates from Danilo Krummrich:
"Deferred probe:
- Fix race where deferred probe timeout work could be permanently
canceled by using mod_delayed_work()
- Fix missing jiffies conversion in deferred_probe_extend_timeout()
- Guard timeout extension with delayed_work_pending() to prevent
premature firing
- Use system_percpu_wq instead of the deprecated system_wq
- Update deferred_probe_timeout documentation
device:
- Replace direct struct device bitfield access (can_match, dma_iommu,
dma_skip_sync, dma_ops_bypass, state_synced, dma_coherent,
of_node_reused, offline, offline_disabled) with flag-based
accessors using bit operations
- Reject devices with unregistered buses
- Delete unused DEVICE_ATTR_PREALLOC()
- Add low-level device attribute macros with const show/store
callbacks, allowing device attributes to reside in read-only memory
- Move core device attributes to read-only memory
- Constify group array pointers in driver_add_groups() /
driver_remove_groups(), struct bus_type, and struct device_driver
device property:
- Fix fwnode reference leak in fwnode_graph_get_endpoint_by_id()
- Initialize all fields of fwnode_handle in fwnode_init()
- Provide swnode_get()/swnode_put() wrappers around kobject_get/put()
- Allow passing struct software_node_ref_args pointers directly to
PROPERTY_ENTRY_REF()
driver_override:
- Migrate amba, cdx, vmbus, and rpmsg to the generic driver_override
infrastructure, fixing a UAF from unsynchronized access to
driver_override in bus match() callbacks
- Remove the now-unused driver_set_override()
firmware loader:
- Fix recursive lock deadlock in device_cache_fw_images() when async
work falls back to synchronous execution
- Fix device reference leak in firmware_upload_register()
platform:
- Pass KBUILD_MODNAME through the platform driver registration macro
to create module symlinks in sysfs for built-in drivers; move
module_kset initialization to a pure_initcall and tegra cbb
registration to core_initcall to ensure correct ordering
- Pass THIS_MODULE implicitly through a coresight_init_driver() macro
sysfs:
- Upgrade OOB write detection in sysfs_kf_seq_show() from printk to
WARN
- Add return value clamping to sysfs_kf_read()
Rust:
- ACPI:
Fix missing match data for PRP0001 by exporting
acpi_of_match_device()
- Auxiliary:
Replace drvdata() with dedicated registration data on
auxiliary_device. drvdata() exposed the driver's bus device private
data beyond the driver's own scope, creating ordering constraints
and forcing the data to outlive all registrations that access it.
Registration data is instead scoped structurally to the
Registration object, making lifecycle ordering enforced by
construction rather than convention.
- Rust-native device driver lifetimes (HRT):
Allow Rust device drivers to carry a lifetime parameter on their
bus device private data, tied to the device binding scope -- the
interval during which a bus device is bound to a driver. Device
resources like pci::Bar<'a> and IoMem<'a> can be stored directly in
the driver's bus device private data with a lifetime bounded by the
binding scope, so the compiler enforces at build time that they do
not outlive the binding. This removes Devres indirection from every
access site and eliminates try_access() failure paths in
destructors.
Bus driver traits use a Generic Associated Type (GAT) Data<'bound>
to introduce the lifetime on the private data, rather than
parameterizing the Driver trait itself. Auxiliary registration
data, where the lifetime is not introduced by a trait callback but
must be threaded through Registration, uses the ForLt trait (a
type-level abstraction for types generic over a lifetime).
Misc:
- Fix DT overlayed devices not probing by reverting the broken
treewide overlay fix and re-running fw_devlink consumer pickup when
an overlay is applied to a bound device
- Use root_device_register() for faux bus root device; add sanity
check for failed bus init
- Fix dev_has_sync_state() data race with READ_ONCE() and move it to
base.h
- Avoid spurious device_links warning when removing a device while
its supplier is unbinding
- Switch ISA bus to dynamic root device
- Fix suspicious RCU usage in kernfs_put()
- Remove devcoredump exit callback
- Constify devfreq_event_class"
* tag 'driver-core-7.2-rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/driver-core/driver-core: (81 commits)
software node: allow passing reference args to PROPERTY_ENTRY_REF()
driver core: platform: set mod_name in driver registration
coresight: pass THIS_MODULE implicitly through a macro
kernel: param: initialize module_kset in a pure_initcall
soc/tegra: cbb: Move driver registration from pure_initcall to core_initcall
firmware_loader: Fix recursive lock in device_cache_fw_images()
driver core: Use system_percpu_wq instead of system_wq
driver core: remove driver_set_override()
rpmsg: use generic driver_override infrastructure
Drivers: hv: vmbus: use generic driver_override infrastructure
cdx: use generic driver_override infrastructure
amba: use generic driver_override infrastructure
rust: devres: add 'static bound to Devres<T>
samples: rust: rust_driver_auxiliary: showcase lifetime-bound registration data
rust: auxiliary: generalize Registration over ForLt
rust: types: add `ForLt` trait for higher-ranked lifetime support
gpu: nova-core: separate driver type from driver data
samples: rust: rust_driver_pci: use HRT lifetime for Bar
rust: io: make IoMem and ExclusiveIoMem lifetime-parameterized
rust: pci: make Bar lifetime-parameterized
...
The PCI_VDEVICE macro assigns 0 to .class and .class_mask to allow the
next value in the initializer to define the value for .driver_data.
So the construct
{
PCI_VDEVICE(INTASHIELD, 0x0D21),
.class = PCI_CLASS_COMMUNICATION_MULTISERIAL << 8,
.class_mask = 0xffff00,
.driver_data = pbn_b2_4_115200,
},
introduced in commit 44e55f1f30 ("serial: 8250_pci: Consistently
define pci_device_ids using named initializers") has conflicting
assignments. In only some configurations (i.e. W=1 for me) that makes
the compiler unhappy.
So convert the two affected items to PCI_DEVICE which doesn't have that
hidden assigment to .class and .class_mask.
Fixes: 44e55f1f30 ("serial: 8250_pci: Consistently define pci_device_ids using named initializers")
Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Closes: https://lore.kernel.org/linux-serial/ah_5qVKOf8LXG1Xo@ashevche-desk.local/T/#ma6eab90ca801b4292639f5c255a89b4033b33d21
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20260603095616.937968-2-u.kleine-koenig@baylibre.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A KASAN null-ptr-deref was observed in vcs_notifier():
BUG: KASAN: null-ptr-deref in vcs_notifier+0x98/0x130
Read of size 2 at addr qmp_cmd_name: qmp_capabilities, arguments: {}
The issue is a race condition in vcs_write(). When the console_lock is
temporarily dropped (to copy data from userspace), the vc_data pointer
obtained from vcs_vc() may become stale. After re-acquiring the lock,
vcs_vc() is called again to re-validate the pointer. If the vc has been
deallocated in the meantime, vcs_vc() returns NULL, and the while loop
breaks (with written > 0). However, after the loop, vcs_scr_updated(vc)
is still called with the now-NULL vc pointer, leading to a null pointer
dereference in the notifier chain (vcs_notifier dereferences param->vc).
Fix this by adding a NULL check for vc before calling vcs_scr_updated().
Fixes: 8fb9ea65c9 ("vc_screen: reload load of struct vc_data pointer in vcs_write() to avoid UAF")
Cc: stable@vger.kernel.org
Signed-off-by: Yi Yang <yiyang13@huawei.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://patch.msgid.link/20260604060734.2914976-1-yiyang13@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In qcom_geni_serial_handle_rx_dma(), geni_se_rx_dma_unprep() clears
port->rx_dma_addr before SE_DMA_RX_LEN_IN is read. If the register is zero,
for example when the RX stale counter fires on an idle line, the handler
returns without calling geni_se_rx_dma_prep().
The next RX DMA interrupt then hits the !port->rx_dma_addr guard and
returns immediately, so the RX DMA buffer is never rearmed and later input
is lost.
Keep the handler on the rearm path when rx_in is zero. Warn about the
unexpected zero-length DMA completion, skip received-data handling, and
always call geni_se_rx_dma_prep().
Fixes: 2aaa43c707 ("tty: serial: qcom-geni-serial: add support for serial engine DMA")
Cc: stable@vger.kernel.org
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Signed-off-by: Viken Dadhaniya <viken.dadhaniya@oss.qualcomm.com>
Link: https://patch.msgid.link/20260528-serial-rx-0-byte-fix-v2-1-b4195cfe342f@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
hvc_iucv_alloc() allocates a send staging buffer for accumulating
outbound terminal characters before they are copied into a separate
IUCV message buffer for transmission to the hypervisor. The staging
buffer itself is never passed to any IUCV function.
This buffer can be allocated with kmalloc() as there's nothing special
about it to go directly to the page allocator.
kmalloc() provides a better API that does not require ugly casts and
kfree() does not need to know the size of the freed object.
Performance difference between kmalloc() and __get_free_pages() is not
measurable as both allocators take an object/page from a per-CPU list for
fast path allocations.
For the slow path the performance is anyway determined by the amount of
reclaim involved rather than by what allocator is used.
Replace use of get_zeroed_page() with kzalloc() and free_page() with
kfree().
Link: https://lore.kernel.org/all/635405e4-9423-4a25-a6e7-e03c8ea0bcbe@redhat.com
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
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Merge tag 'v7.1-rc6' into tty-next
We need the tty/serial fixes in here as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Enable modular build since the driver now has a proper module_exit()
handler. There's nothing specific to DZ hardware to prevent driver
unloading and reloading from working.
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Link: https://patch.msgid.link/alpine.DEB.2.21.2605062331420.46195@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Prevent a crash from happening as the first serial port is initialised:
Console: switching to mono frame buffer device 160x64
fb0: PMAG-AA frame buffer device at tc0
DECstation Z85C30 serial driver version 0.10
CPU 0 Unable to handle kernel paging request at virtual address 0000002c, epc == 803ab00c, ra == 803aafe0
Oops[#1]:
CPU: 0 PID: 1 Comm: swapper Not tainted 6.4.0-rc3-00031-g84a9582fd203-dirty #57
$ 0 : 00000000 10012c00 803aaeb0 00000000
$ 4 : 80e12f60 80e12f50 80e12f58 81000030
$ 8 : 00000000 805ff37c 00000000 33433538
$12 : 65732030 00000006 80c2915d 6c616972
$16 : 80e12f00 807b7630 00000000 00000000
$20 : 00000004 00000348 000001a0 807623b8
$24 : 00000018 00000000
$28 : 80c24000 80c25d60 8078b148 803aafe0
Hi : 00000000
Lo : 00000000
epc : 803ab00c serial_base_ctrl_add+0x78/0xf4
ra : 803aafe0 serial_base_ctrl_add+0x4c/0xf4
Status: 10012c03 KERNEL EXL IE
Cause : 00000008 (ExcCode 02)
BadVA : 0000002c
PrId : 00000440 (R4400SC)
Modules linked in:
Process swapper (pid: 1, threadinfo=(ptrval), task=(ptrval), tls=00000000)
Stack : 80760000 00000cc0 00400044 00400040 803aa02c 80d61ab8 00000000 807b7630
80760000 807623b8 807b7628 803aa644 80386998 00000000 80e17780 80220f68
80e17780 80d61ab8 80c17d80 80e17780 80e17780 8063c798 80e17780 80383fa0
00000010 80e17780 00000000 80386998 807a0000 00000000 00400040 8038f848
807623b8 80d61ab8 00000004 80e17780 00000000 803a68e4 80c25e2c 803bb884
...
Call Trace:
[<803ab00c>] serial_base_ctrl_add+0x78/0xf4
[<803aa644>] serial_core_register_port+0x174/0x69c
[<8077e9ac>] zs_init+0xc8/0xfc
[<800404d4>] do_one_initcall+0x40/0x2ac
[<8076cecc>] kernel_init_freeable+0x1e4/0x270
[<80605bec>] kernel_init+0x20/0x108
[<800431e8>] ret_from_kernel_thread+0x14/0x1c
Code: 2442aeb0 ae120024 ae0200d0 <8c67002c> 50e00001 8c670000 3c06806e 3c05806e afb30010
---[ end trace 0000000000000000 ]---
(report at the offending commit) -- where a pointer is dereferenced that
has been derived from a null pointer to the port's parent device.
Since no device is available with legacy probing and it's not anymore a
preferable way to discover devices anyway, switch the driver to using a
platform device and use it as the port's parent device. Update resource
handling accordingly and only request the actual span of addresses used
within the slot, which will have had its resource already requested by
generic platform device code.
Use platform_driver_probe() not just because SCC devices are fixed with
solder on board and not straightforward to remove, but foremost because
the associated TTY's major device number is the same as used by the dz
driver and the first driver to claim it will prevent the other one from
using it. Either one DZ device or some SCC devices will be present in a
given system but never both at a time, and therefore we want the major
device number to be claimed by the first driver to actually successfully
bind to its device and platform_driver_probe() is a way to fulfil that.
An unfortunate consequence of the switch to a platform device is we now
hand the console over from the bootconsole much later in the bootstrap.
The firmware console handler appears good enough though to work so late
and in particular with interrupts enabled.
Since there is one way only remaining to reach zs_reset() now, remove
the port initialisation marker as no longer needed and go through the
channel reset unconditionally.
Fixes: 84a9582fd2 ("serial: core: Start managing serial controllers to enable runtime PM")
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: stable@vger.kernel.org # needs to use .remove_new for <= 6.10
Link: https://patch.msgid.link/alpine.DEB.2.21.2605062328480.46195@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Prevent a crash from happening as the first serial port is initialised:
Console: switching to colour frame buffer device 160x64
tgafb: SFB+ detected, rev=0x02
fb0: Digital ZLX-E1 frame buffer device at 0x1e000000
DECstation DZ serial driver version 1.04
CPU 0 Unable to handle kernel paging request at virtual address 000000bc, epc == 8048b3a4, ra == 80470a78
Oops[#1]:
CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.19.0-dirty #35 NONE
$ 0 : 00000000 1000ac00 00000004 804707ac
$ 4 : 00000000 80e20850 80e20858 81000030
$ 8 : 00000000 8072c81c 00000008 fefefeff
$12 : 6c616972 00000006 80c5917f 69726420
$16 : 80e20800 00000000 808f8968 80e20800
$20 : 00000000 807f5a90 808b0094 808d3bc8
$24 : 00000018 80479030
$28 : 80c2e000 80c2fd70 00000069 80470a78
Hi : 00000004
Lo : 00000000
epc : 8048b3a4 __dev_fwnode+0x0/0xc
ra : 80470a78 serial_base_ctrl_add+0xa0/0x168
Status: 1000ac04 IEp
Cause : 30000008 (ExcCode 02)
BadVA : 000000bc
PrId : 00000220 (R3000)
Modules linked in:
Process swapper/0 (pid: 1, threadinfo=(ptrval), task=(ptrval), tls=00000000)
Stack : 00400044 00400040 8046f4cc 00000000 808a6148 808a0000 808f8968 8086983c
808e0000 8046fc84 1000ac01 00000028 80e20700 802ba3f8 80e20700 80d34a94
80c1b900 80e20700 80e20700 80e20700 80e20700 80444650 00000000 00000000
00000000 807f5a90 808b0094 80447080 00400040 808e0000 80d34a94 808a6148
80d34a94 00000004 80e20700 00000000 8076974c 80469810 80c2fe3c 1000ac01
...
Call Trace:
[<8048b3a4>] __dev_fwnode+0x0/0xc
[<80470a78>] serial_base_ctrl_add+0xa0/0x168
[<8046fc84>] serial_core_register_port+0x1c8/0x974
[<808c6af0>] dz_init+0x74/0xc8
[<800470e0>] do_one_initcall+0x44/0x2d4
[<808b111c>] kernel_init_freeable+0x258/0x308
[<8072e434>] kernel_init+0x20/0x114
[<80049cd0>] ret_from_kernel_thread+0x14/0x1c
Code: 27bd0018 03e00008 2402ffea <8c8200bc> 03e00008 00000000 27bdffc0 afbe0038 afb30024
---[ end trace 0000000000000000 ]---
-- where a pointer is dereferenced that has been derived from a null
pointer to the port's parent device.
Since no device is available with legacy probing and it's not anymore a
preferable way to discover devices anyway, switch the driver to using a
platform device and use it as the port's parent device. Update resource
handling accordingly and only request the actual span of addresses used
within the slot, which will have had its resource already requested by
generic platform device code.
Use platform_driver_probe() not just because the DZ device is fixed with
solder on board and not straightforward to remove, but foremost because
the associated TTY's major device number is the same as used by the zs
driver and the first driver to claim it will prevent the other one from
using it. Either one DZ device or some SCC devices will be present in a
given system but never both at a time, and therefore we want the major
device number to be claimed by the first driver to actually successfully
bind to its device and platform_driver_probe() is a way to fulfil that.
An unfortunate consequence of the switch to a platform device is we now
hand the console over from the bootconsole much later in the bootstrap.
The firmware console handler appears good enough though to work so late
and in particular with interrupts enabled.
Conversely only starting the console port so late lets the reset code
fully utilise our delay handlers, so switch from udelay() to fsleep()
for transmitter draining so as to avoid busy-waiting for an excessive
amount of time.
Fixes: 84a9582fd2 ("serial: core: Start managing serial controllers to enable runtime PM")
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: stable@vger.kernel.org # needs to use .remove_new for <= 6.10
Link: https://patch.msgid.link/alpine.DEB.2.21.2605062326540.46195@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Switch the driver to using the channel reset rather than hardware reset,
simplifying handling by removing an interference between channels that
causes the other channel to become uninitialised afterwards.
There is little difference between the two kinds of reset in terms of
register settings that result, and we initialise the whole register set
right away anyway. However this prevents a hang from happening should
the console output handler in the firmware try to access the other port
whose transmitter has been disabled and line parameters messed up.
For example this will happen if the keyboard port (port A) is chosen for
the system console, unusually but not insanely for a headless system, as
the port is wired to a standard DA-15 connector and an adapter can be
easily made. Or with the next change in place this would happen for the
regular console port (port B), since the keyboard port (port A) will be
initialised first.
Just remove the unnecessary complication then, a channel reset is good
enough. We still need the initialisation marker, now per channel rather
than per SCC, as for the console port zs_reset() will be called twice:
once early on via zs_serial_console_init() for the console setup only,
and then again via zs_config_port() as the port is associated with a TTY
device.
Fixes: 8b4a40809e ("zs: move to the serial subsystem")
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: stable@vger.kernel.org # v2.6.23+
Link: https://patch.msgid.link/alpine.DEB.2.21.2605062323430.46195@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Calling zs_reset() in the course of setting up the serial device causes
line parameters to be reset and the transmitter disabled. We've been
lucky in that no message is usually produced to the kernel log between
this call and the later call to uart_set_options() in the course of
console setup done by zs_serial_console_init(), or the system would hang
as the console output handler in the firmware tried to access a port the
transmitter of which has been disabled and line parameters messed up.
This will change with the next change to the driver, so fix zs_reset()
such that line parameters are set for 9600n8 console operation as with
the system firmware and the transmitter re-enabled after reset. This
also means zs_pm() serves no purpose anymore, so drop it.
Fixes: 8b4a40809e ("zs: move to the serial subsystem")
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: stable@vger.kernel.org # v2.6.23+
Link: https://patch.msgid.link/alpine.DEB.2.21.2605062308040.46195@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Calling dz_reset() in the course of setting up the serial device causes
line parameters to be reset and the transmitter disabled. We've been
lucky in that no message is usually produced to the kernel log between
this call and the later call to uart_set_options() in the course of
console setup done by dz_serial_console_init(), or the system would hang
as the console output handler in the firmware tried to access a port the
transmitter of which has been disabled and line parameters messed up.
This will change with the next change to the driver, so fix dz_reset()
such that line parameters are set for 9600n8 console operation as with
the system firmware and the transmitter re-enabled after reset. This
also means dz_pm() serves no purpose anymore, so drop it.
Fixes: e6ee512f5a ("dz.c: Resource management")
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: stable@vger.kernel.org # v2.6.25+
Link: https://patch.msgid.link/alpine.DEB.2.21.2605062302010.46195@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the DZ interface as implemented by the DC7085 gate array the serial
transmitters are double buffered, meaning that at the time a transmitter
is ready to accept the next character there is one in the transmit shift
register still being sent to the line. Issuing a master clear at this
time causes this character to be lost, so wait an extra amount of time
sufficient for the transmit shift register to drain at 9600bps, which is
the baud rate setting used by the firmware console.
Mind the specified 1.4us TRDY recovery time in the course and continue
using iob() as the completion barrier, since the platforms involved use
a write buffer that can delay and combine writes, and reorder them with
respect to reads regardless of the MMIO locations accessed and we still
lack a platform-independent handler for that.
When called from dz_serial_console_init() this is too early for fsleep()
to work and even before lpj has been calculated and therefore the delay
is actually not sufficient for the transmitter to drain and is merely a
placeholder now. This will be addressed in a follow-up change.
Fixes: e6ee512f5a ("dz.c: Resource management")
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: stable@vger.kernel.org # v2.6.25+
Link: https://patch.msgid.link/alpine.DEB.2.21.2605062259080.46195@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dw8250_handle_irq() calls serial8250_handle_irq_locked() with the port
lock held via guard(uart_port_lock_irqsave). The guard destructor is
plain uart_port_unlock_irqrestore(), so a SysRq character captured into
port->sysrq_ch by uart_prepare_sysrq_char() is dropped without ever
being dispatched to handle_sysrq().
This is the same regression pattern as in serial8250_handle_irq(),
introduced when 883c5a2bc9 ("serial: 8250_dw: Rework
dw8250_handle_irq() locking and IIR handling") moved the function to
the guard()-based locking scheme without using the sysrq-aware unlock
helper.
Switch to guard(uart_port_lock_check_sysrq_irqsave) so that captured
sysrq_ch is dispatched on scope exit, matching the fix in
serial8250_handle_irq().
Fixes: 883c5a2bc9 ("serial: 8250_dw: Rework dw8250_handle_irq() locking and IIR handling")
Cc: stable@vger.kernel.org
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Jacques Nilo <jnilo@free.fr>
Link: https://patch.msgid.link/ed56fcaf4af24e4ed011a7bce206e0182acb761c.1778675349.git.jnilo@free.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial8250_handle_irq() captures a SysRq character into port->sysrq_ch
inside serial8250_handle_irq_locked() via uart_prepare_sysrq_char()
(reached from serial8250_read_char()). Dispatch of that captured
character to handle_sysrq() is expected to happen at port-unlock time,
through uart_unlock_and_check_sysrq[_irqrestore]().
After commit 8324a54f60 ("serial: 8250: Add
serial8250_handle_irq_locked()") the function was reduced to a wrapper
that takes the port lock via guard(uart_port_lock_irqsave) whose
destructor is plain uart_port_unlock_irqrestore(). The sysrq-aware
unlock helper is no longer called, so port->sysrq_ch is captured but
never dispatched: BREAK + SysRq key is consumed silently.
This was the very condition Johan Hovold's 853a9ae29e ("serial:
8250: fix handle_irq locking", 2021) introduced
uart_unlock_and_check_sysrq_irqrestore() to address.
Switch to the new guard(uart_port_lock_check_sysrq_irqsave), whose
destructor is the sysrq-aware unlock helper, restoring the pre-split
behaviour. Update the Context: comment on serial8250_handle_irq_locked()
so future HW-specific 8250 wrappers know to use the same guard or the
explicit sysrq-aware unlock.
Verified on RTL8196E with CONFIG_MAGIC_SYSRQ_SERIAL=y: BREAK + 'h' on
the console UART produces the SysRq help dump in dmesg and the brk
counter in /proc/tty/driver/serial increments correctly.
Fixes: 8324a54f60 ("serial: 8250: Add serial8250_handle_irq_locked()")
Cc: stable@vger.kernel.org
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Jacques Nilo <jnilo@free.fr>
Link: https://patch.msgid.link/52692ae6c3501f7940347cef364ad7fcacaab7e5.1778675349.git.jnilo@free.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Sashiko identified a deadlock when the console flow is engaged [1].
When console flow control is enabled (UPF_CONS_FLOW),
s3c24xx_serial_stop_tx() calls s3c24xx_serial_rx_enable() and
s3c24xx_serial_start_tx() calls s3c24xx_serial_rx_disable().
The serial core framework invokes the .stop_tx() and .start_tx()
callbacks with the port->lock spinlock already held. Furthermore, all
internal driver paths that invoke stop_tx (such as the DMA TX
completion handler s3c24xx_serial_tx_dma_complete() or the PIO TX IRQ
handler s3c24xx_serial_tx_irq()) also acquire port->lock prior to
calling it. (Note that s3c24xx_serial_start_tx() is only invoked by the
serial core).
However, s3c24xx_serial_rx_enable() and s3c24xx_serial_rx_disable()
unconditionally attempt to acquire port->lock again using
uart_port_lock_irqsave(). Since spinlocks are not recursive, this
causes a deadlock on the same CPU when console flow control is engaged.
Remove the redundant lock acquisition from both rx helper functions.
Cc: stable <stable@kernel.org>
Fixes: b497549a03 ("[ARM] S3C24XX: Split serial driver into core and per-cpu drivers")
Reported-by: John Ogness <john.ogness@linutronix.de>
Closes: https://sashiko.dev/#/patchset/20260506121606.5805-1-john.ogness%40linutronix.de [1]
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://patch.msgid.link/20260515-samsung-tty-flow-control-deadlock-v1-1-93255edbc9bc@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
altera_jtaguart_probe() maps the register window before registering the
UART port, but it ignores failures from uart_add_one_port(). If port
registration fails, probe still returns success and the mapping remains
live until a later remove path that is not part of probe failure cleanup.
Return the uart_add_one_port() error and unmap the register window on
that failure path.
This issue was identified during our ongoing static-analysis research while
reviewing kernel code.
Fixes: 5bcd601049 ("serial: Add driver for the Altera JTAG UART")
Cc: stable <stable@kernel.org>
Co-developed-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Myeonghun Pak <mhun512@gmail.com>
Link: https://patch.msgid.link/20260512065837.79528-1-mhun512@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The hot path in vc_process_ucs() asks two independent questions about the
same code point -- "is it double-width?" and "is it zero-width?" -- and
was answering each with its own bsearch over its own table. For anything
past the leading bounds check that meant two scans of the BMP width
tables back to back for what is logically a single lookup.
Replace both with one ucs_get_width(cp) returning 0, 1, or 2 in a single
bsearch, while keeping the total table footprint at the same 2384 B as
before.
To do so, merge the zero-width and double-width ranges per region into
one sorted-by-`first` table. BMP entries stay 4 bytes; per-entry width
is hosted in spare bits of the non-BMP table's `last` field. Non-BMP
code points use only 20 of 32 bits, so each u32 has 12 unused high bits.
Store first/last shifted left by 12 and use the low 12 bits of `last`
for metadata: bit 11 is this entry's own width flag, bits 0..7 host an
8-bit chunk of the BMP double-width bitmap. Because the metadata bits
sit strictly below the lowest cp-scale bit, the bsearch comparator
remains a plain u32 compare on shifted keys with no masking.
In vc_process_ucs() the overwhelmingly common single-width path now
collapses to a single predicted branch:
if (likely(w == 1))
return 1;
Note: scripts/checkpatch.pl complains about "Macros with complex values
should be enclosed in parentheses" for the BMP_*WIDTH and
RANGE_*WIDTH macros. They are deliberately defined to expand to a
comma-separated (first, last) pair so they can populate the two
adjacent fields of a struct initializer; wrapping them in
parentheses would turn that into a comma-expression and defeat
the whole construction. Please ignore.
Signed-off-by: Nicolas Pitre <nico@fluxnic.net>
Link: https://patch.msgid.link/20260515034857.2514225-1-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are rare cases in which the host gets stuck in the ISR because it
is flooded with messages during the startup phase.
The reason for the soft lockup in the ISR is the missing FIFO error IRQ
(FIFOE) handling. Not handling it and reporting IRQ_HANDLED triggers
the IRQ immediately again.
Fix this by adding a check for the FIFOE status and clearing the FIFO
if no data is ready (DR).
This behavior was observed on an AM62L device which uses the OMAP 8250
driver. Fix it for all 8250 drivers, since the OMAP driver's special
IRQ setup handling may trigger this behavior more frequently, but it
is not ensured that other 8250 drivers aren't affected.
Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Link: https://patch.msgid.link/20260519-v7-1-topic-serial-8250-v1-1-56b04293a246@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The plain text binding file was superseded by the YAML schema in
commit d50f974c4f ("dt-bindings: serial: Convert rs485 bindings
to json-schema"). The file now contains only a redirect notice.
Remove it, and update references in serial_core.c and
serial-rs485.rst to point to the YAML schema.
Signed-off-by: Akash Sukhavasi <akash.sukhavasi@gmail.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://patch.msgid.link/20260521162137.6325-1-akash.sukhavasi@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
While being less compact, using named initializers allows to more easily
see which members of the structs are assigned which value without having
to lookup the declaration of the struct. And it's also more robust
against changes to the struct definition.
The mentioned robustness is relevant for a planned change to struct
i2c_device_id that replaces .driver_data by an anonymous union.
While touching all these arrays, unify usage of whitespace in the list
terminator.
This patch doesn't modify the compiled arrays, only their representation
in source form benefits. The former was confirmed with x86 and arm64
builds.
Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
Link: https://patch.msgid.link/20260518101456.632410-2-u.kleine-koenig@baylibre.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The clock notifier and matching work_struct in dw8250_data were added
in 2020 for the Baikal-T1 SoC, whose multiple UART ports share a
single reference clock and need to be informed when another consumer
re-rates that clock.
Baikal SoC support has since been removed from the kernel (see e.g.
commit 5d6c477687 ("clk: baikal-t1: Remove not-going-to-be-supported
code for Baikal SoC") and the matching removals across bus/, mtd/,
PCI/, hwmon/, memory/). No remaining in-tree user needs the
cross-device baudclk rate-change notification path: the only
configuration that wired up the notifier was Baikal-T1's shared
reference clock topology.
Drop the now-unused clock-notifier and its deferred-update worker:
- struct dw8250_data fields clk_notifier and clk_work,
- the clk_to_dw8250_data() and work_to_dw8250_data() helpers,
- the dw8250_clk_work_cb() and dw8250_clk_notifier_cb() callbacks,
- the INIT_WORK / notifier_call setup in dw8250_probe(),
- the clk_notifier_register() / queue_work() in dw8250_probe(),
- the matching clk_notifier_unregister() / flush_work() in
dw8250_remove(),
- the stale comment in dw8250_set_termios() about the worker
blocking,
- the linux/notifier.h and linux/workqueue.h includes that are
no longer used.
dw8250_set_termios() keeps calling clk_set_rate() directly, which is
all the remaining single-UART configurations require.
Signed-off-by: Stepan Ionichev <sozdayvek@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20260514143746.23671-3-sozdayvek@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dw8250_probe() registers the 8250 port via serial8250_register_8250_port()
and then, if the device has a clock, registers a clock notifier. If
clk_notifier_register() fails, probe returns the error but leaves the
8250 port registered. The matching serial8250_unregister_port() lives
in dw8250_remove(), which is not called when probe fails, so the port
slot stays occupied until the device is rebound or the system is
rebooted. The devm-allocated driver data is freed while the port still
references it (via the saved private_data and serial_in/serial_out
callbacks), so any access to that port slot before a rebind is a
use-after-free hazard.
Unregister the port on the clk_notifier_register() error path.
Fixes: cc816969d7 ("serial: 8250_dw: Fix common clocks usage race condition")
Cc: stable@vger.kernel.org
Signed-off-by: Stepan Ionichev <sozdayvek@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20260514143746.23671-2-sozdayvek@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is based on code removed in commit 89d4f98ae9 ("ARM: remove zte
zx platform"). I did not bring back the zx29-uart .compatible as the
arm,primecell-periphid does the job.
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Stefan Dösinger <stefandoesinger@gmail.com>
Link: https://patch.msgid.link/20260514-zx29uart-v1-2-68470ecc3977@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The kernel documentation specifies that the console option 'r' can
be used to enable hardware flow control for console writes. The 8250
driver does include code for hardware flow control on the console if
cons_flow is set, but there is no code path that actually sets this.
However, that is not the only issue. The problems are:
1. Specifying the console option 'r' does not lead to cons_flow being
set.
2. Even if cons_flow would be set, serial8250_register_8250_port()
clears it.
3. When the console option 'r' is specified, uart_set_options()
attempts to initialize the port for CRTSCTS. However, afterwards
it does not set the UPSTAT_CTS_ENABLE status bit and therefore on
boot, uart_cts_enabled() is always false. This policy bit is
important for console drivers as a criteria if they may poll CTS.
4. Even though uart_set_options() attempts to initialize the port
for CRTSCTS, the 8250 set_termios() callback does not enable the
RTS signal (TIOCM_RTS) and thus the hardware is not properly
initialized for CTS polling.
5. Even if modem control was properly setup for CTS polling
(TIOCM_RTS), uart_configure_port() clears TIOCM_RTS, thus
breaking CTS polling.
6. wait_for_xmitr() and serial8250_console_write() use cons_flow
to decide if CTS polling should occur. However, the condition
should also include a check that it is not in RS485 mode and
CRTSCTS is actually enabled in the hardware.
Address all these issues as conservatively as possible by gating them
behind checks focussed on the user specifying console hardware flow
control support and the hardware being configured for CTS polling
at the time of the write to the UART.
Since checking the UPSTAT_CTS_ENABLE status bit is a part of the new
condition gate, these changes also support runtime termios updates to
disable/enable CRTSCTS.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://patch.msgid.link/20260511152706.151498-4-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
wait_for_xmitr() calls wait_for_lsr() to wait for the transmission
registers to be empty. wait_for_lsr() can timeout after a reasonable
amount of time.
When console flow control is active, wait_for_xmitr() additionally
polls CTS, waiting for the peer to signal that it is ready to receive
more data.
If hardware flow control is enabled (auto CTS) and the peer deasserts
CTS, wait_for_lsr() will timeout. If additionally console flow
control is active and while polling CTS the peer asserts CTS, the
console will assume it can immediately transmit, even though the
transmission registers may not be empty. This can lead to data loss.
Avoid this problem by performing an extra wait_for_lsr() upon CTS
assertion if wait_for_lsr() previously timed out.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://patch.msgid.link/20260511152706.151498-3-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since console flow control policy is no longer part of uart_port.flags,
explicitly set the policy for the port.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://patch.msgid.link/20260511152706.151498-2-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial8250_register_8250_port() conditionally copies uart->port.dev
from up->port.dev only when up->port.dev is non-NULL:
if (up->port.dev) {
uart->port.dev = up->port.dev;
...
}
So if both the existing uart slot and up have a NULL ->dev,
uart->port.dev remains NULL. The very next ACPI companion check
then dereferences it unconditionally:
if (!has_acpi_companion(uart->port.dev)) {
has_acpi_companion() reads dev->fwnode without a NULL guard
(include/linux/acpi.h), so this NULL-derefs the kernel for the
remaining no-dev case rather than just skipping the
mctrl_gpio_init() initialisation as intended.
smatch flags the inconsistency:
drivers/tty/serial/8250/8250_core.c:767
serial8250_register_8250_port() error: 'uart->port.dev' could be
null (see line 719)
Guard the call with a NULL check so register continues to work
for callers that legitimately have no parent device (legacy
non-OF/non-ACPI registrations).
No functional change for callers that pass a non-NULL ->dev.
Signed-off-by: Stepan Ionichev <sozdayvek@gmail.com>
Link: https://patch.msgid.link/20260508181237.11146-1-sozdayvek@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since commit 20ffe4b333 ("serial: max310x: allow driver to be built with
SPI or I2C"), if I2C is enabled and SPI_MASTER is disabled, we have these
compile errors:
drivers/tty/serial/max310x.c: In function 'max310x_uart_init':
drivers/tty/serial/max310x.c: error: 'max310x_spi_driver' undeclared...
drivers/tty/serial/max310x.c: In function ‘max310x_uart_init’:
drivers/tty/serial/max310x.c: error: label ‘err_spi_register’
defined but not used...
drivers/tty/serial/max310x.c: error: ‘regcfg’ defined but not used
Fix by properly encapsulating i2c/spi code/variables in their respective
context with IS_ENABLED() macros for CONFIG_I2C and CONFIG_SPI_MASTER.
Also fix link failure with SERIAL_MAX310X=y and I2C=m by modifying Kconfig
depends.
Fixes: 20ffe4b333 ("serial: max310x: allow driver to be built with SPI or I2C")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202605121847.N9DVLNg2-lkp@intel.com/
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260521153333.2336642-1-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The mdacon driver supports using ISA MDA or Hercules-compatible display
adapters as a secondary text console. This was commonly used in the
1990s and earlier for debugging software which took over the primary
display. It is highly unlikely anyone is doing so nowadays because
serial consoles and much better methods of debugging exist.
The driver is not enabled by any defconfig, nor any of the
dozens of distro configs collected at [1]. It has been relegated to VTs
13-16 since commit 0b9cf3aa6b ("mdacon messing up default vc's - set
default to vc13-16 again") in Linux 2.6.27 (and before Linux 2.5.53 -
see the link in the message of the above commit). The change in 2.6.27
was done because it was incorrectly detecting non-MDA adapters as MDA
and taking over all VTs, rendering them unusable.
Furthermore, vgacon supports using MDA/Hercules-compatible adapters as
the primary text console, so any systems with only one of these
adapters were already using vgacon and will not experience any loss in
functionality from the removal of this driver.
Given all of these factors, the mdacon driver is likely entirely
unused. Remove it.
[1] f0bee86a13
Signed-off-by: Ethan Nelson-Moore <enelsonmoore@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
When CONFIG_SERIAL_QCOM_GENI_CONSOLE is disabled, the driver still
advertises the debug UART compatible strings ("qcom,geni-debug-uart"
and "qcom,sa8255p-geni-debug-uart") in its of_match table. This lets the
driver match and probe console UART DT nodes even though console
support is not built. As a result, the console port is never registered
with the UART core and uart_add_one_port() fails with -EINVAL.
Fix this by only including the debug UART compatible entries in the
match table when CONFIG_SERIAL_QCOM_GENI_CONSOLE is enabled, preventing
the driver from probing console UART nodes when console support is
absent.
Reviewed-by: Praveen Talari <praveen.talari@oss.qualcomm.com>
Signed-off-by: Aniket Randive <aniket.randive@oss.qualcomm.com>
Link: https://patch.msgid.link/20260504101045.1084672-1-aniket.randive@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add comments to help clarify the provenance of the various hardcoded values
used in computing the ref clk.
Assisted-by: Gemini:Pro
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260417-max310x-2-v1-10-b424e105ecac@dimonoff.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
txlen, to_send and tail variables are only used within the while() loop.
Move them to that scope to keep them closer to their usage and improve
readability.
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260417-max310x-2-v1-9-b424e105ecac@dimonoff.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If SPI is disabled, the max310x driver cannot be selected. Allow driver to
be selected if either I2C or SPI is set.
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260417-max310x-2-v1-8-b424e105ecac@dimonoff.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The same basic code is duplicated for each of the four PLL multiplier
values, so simplify and streamline it. Doing so allows us to avoid
some unnecessary (fdiv * factor) multiplications for some fdiv values and
replace the second "if" statement with an "else if" and avoid a useless
comparison.
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260417-max310x-2-v1-5-b424e105ecac@dimonoff.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The baudrate used to compute the best error was changed from 115200 to
460800 in commit 35240ba26a ("tty: max310x: Fix invalid baudrate
divisors calculator"), but the comment was not updated, so fix it.
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260417-max310x-2-v1-4-b424e105ecac@dimonoff.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Having max310x_set_ref_clk() return an s32 as both an error code
and a frequency value is ambiguous. Fix by passing a pointer to the
frequency value that will then be updated, and simply return a status.
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260417-max310x-2-v1-3-b424e105ecac@dimonoff.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
besterr was defined as a signed type was to make sure that the first call
to max310x_update_best_err() would always set besterr. Also there is no
need for it to be a long. By changing its type to unsigned int and initial
value to UINT_MAX, max310x_update_best_err() can be simplified and be more
efficient while achieving the same initial result.
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260417-max310x-2-v1-2-b424e105ecac@dimonoff.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
max310x_set_ref_clk() returns a 32-bits clock value, so there is no need
to have parameters and intermediate values defined as long. Change
clock and freq types to int.
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260417-max310x-2-v1-1-b424e105ecac@dimonoff.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If a device has a minimum baud rate > 9600 bauds, and a new termios baud
rate of 0 (hang up) is requested, uart_get_baud_rate() will return 0.
Most drivers do not check this return value and call uart_update_timeout()
with this zero baud rate, which will trigger a "Division by zero in kernel"
fault:
stty -F /dev/ttySC0 0
Division by zero in kernel.
...
Fix by returning the larger of 9600 or min for the B0 case. This now
ensures that a non-zero baud rate is returned, and greatly simplifies the
code.
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260410152022.2146488-6-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Simplify the clipping logic in uart_get_baud_rate() to improve code
readability.
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260410152022.2146488-5-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The minimum baud rate supported by this driver is 0, so even for the B0
case, uart_get_baud_rate() will return 9600, not zero. This check predates
commit 16ae2a877b ("serial: Fix crash if the minimum rate of the device
is > 9600 baud") and is no longer necessary so remove it.
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260410152022.2146488-3-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The minimum baud rate supported by this driver is 300, so even for the B0
case, uart_get_baud_rate() will return 9600, not zero. This check predates
commit 16ae2a877b ("serial: Fix crash if the minimum rate of the device
is > 9600 baud") and is no longer necessary so remove it.
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260410152022.2146488-2-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When uart_flush_buffer() runs before the DMA completion IRQ is delivered,
the following race can occur (all steps serialized by uart_port_lock):
1. DMA starts: tx_remaining = N, kfifo contains N bytes
2. DMA completes in hardware; IRQ is pending but not yet delivered
3. uart_flush_buffer() acquires the port lock and calls kfifo_reset(),
making kfifo_len() = 0 while tx_remaining remains N
4. uart_flush_buffer() releases the port lock
5. DMA IRQ fires; handle_tx_dma() acquires the port lock and calls
uart_xmit_advance(uport, tx_remaining) on an empty kfifo
uart_xmit_advance() increments kfifo->out by tx_remaining. Since
kfifo_reset() already set both in and out to 0, out wraps past in,
causing kfifo_len() to return UART_XMIT_SIZE - tx_remaining. The next
start_tx_dma() call then submits a DMA transfer of stale buffer data.
Fix this by snapshotting kfifo_len() at the start of handle_tx_dma()
and skipping uart_xmit_advance() when fifo_len < tx_remaining, which
indicates the kfifo was reset by a preceding flush.
Fixes: 2aaa43c707 ("tty: serial: qcom-geni-serial: add support for serial engine DMA")
Cc: stable <stable@kernel.org>
Signed-off-by: Viken Dadhaniya <viken.dadhaniya@oss.qualcomm.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Link: https://patch.msgid.link/20260506-serial-dma-stale-tx-buf-v1-1-e3ccb360d719@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
lpuart_start_rx_dma() allocates sport->rx_ring.buf with kzalloc() and
then maps a scatterlist via dma_map_sg(). On three subsequent error
paths the function returns directly without releasing those resources:
- when dma_map_sg() returns 0 (-EINVAL):
ring->buf is leaked.
- when dmaengine_slave_config() fails:
ring->buf and the DMA mapping are leaked.
- when dmaengine_prep_dma_cyclic() returns NULL:
ring->buf and the DMA mapping are leaked.
The sole cleanup path, lpuart_dma_rx_free(), is only reached when
lpuart_dma_rx_use is set, and the caller lpuart_rx_dma_startup() clears
that flag on failure of lpuart_start_rx_dma(). So these resources are
permanently leaked on every failure in this function. Repeated port
open/close or termios changes under error conditions will slowly consume
memory and leave stale streaming DMA mappings behind.
Fix it by introducing two error labels that unmap the scatterlist and
free the ring buffer as appropriate. While here, replace the misleading
-EFAULT (bad userspace pointer) returned when dmaengine_prep_dma_cyclic()
fails with the more accurate -ENOMEM, matching how other dmaengine users
in the tree treat this failure.
No functional change on the success path.
Fixes: 5887ad43ee ("tty: serial: fsl_lpuart: Use cyclic DMA for Rx")
Cc: stable <stable@kernel.org>
Signed-off-by: Shitalkumar Gandhi <shitalkumar.gandhi@cambiumnetworks.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260420135903.2062024-1-shitalkumar.gandhi@cambiumnetworks.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
UART_RX_PAR_EN is incorrectly defined as bit 3, which triggers false
framing errors (S_GP_IRQ_1_EN) and causes received data to be dropped
when parity is enabled and the parity bit is 0.
Define UART_RX_PAR_EN as bit 4 of the SE_UART_RX_TRANS_CFG register, as
specified in the reference manual.
Fixes: c4f528795d ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP")
Cc: stable <stable@kernel.org>
Signed-off-by: Prasanna S <prasanna.s@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Link: https://patch.msgid.link/20260428-serial-bit-correct-v1-1-9131ad5b97d8@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The sci_request_port() function uses request_mem_region() to reserve
I/O memory, but in the error path when sci_remap_port() fails, it
incorrectly calls release_resource() instead of release_mem_region().
This mismatch can cause resource accounting issues. Fix it by using
the correct release function, consistent with sci_release_port().
Fixes: e265164708 ("serial: sh-sci: Handle port memory region reservations.")
Cc: stable <stable@kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Closes: https://lore.kernel.org/r/202604032356.SzEjYkBC-lkp@intel.com/
Signed-off-by: Hongling Zeng <zenghongling@kylinos.cn>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20260421065737.724187-1-zenghongling@kylinos.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a check for dma_alloc_coherent() failure to prevent a potential
NULL pointer dereference in dma_handle_rx(). Properly release DMA
channels and the PCI device reference using a goto ladder if the
allocation fails.
Fixes: 3c6a483275 ("Serial: EG20T: add PCH_UART driver")
Cc: stable <stable@kernel.org>
Signed-off-by: Zhaoyang Yu <2426767509@qq.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/tencent_E328416B7CFD436F6029F2DF02AD7ED89C08@qq.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix a thinko in the status interrupt handler that has caused counters
for the RI and DSR modem line transitions to be used for the other line
each.
Fixes: 8b4a40809e ("zs: move to the serial subsystem")
Cc: stable <stable@kernel.org>
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Link: https://patch.msgid.link/alpine.DEB.2.21.2604101747110.29980@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The UltraRISC DP1000 UART does not provide the standard CPR register used
by 8250_dw to discover port capabilities.
Provide a fixed CPR value for the DP1000-specific compatible so the
driver can configure the port correctly.
Signed-off-by: Jia Wang <wangjia@ultrarisc.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20260429-ultrarisc-serial-v7-4-e475cce9e274@ultrarisc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Replace the magic CPR value for Renesas RZ/N1 with a composition using
DW_UART_CPR_* bit/field definitions and FIELD_PREP_CONST().
Introduce a helper macro to convert a FIFO size (bytes) into the CPR
FIFO_MODE field value, with BUILD_BUG_ON_ZERO() checks for alignment and
bounds. Use it to replace the literal FIFO_MODE values in the RZN1.
Signed-off-by: Jia Wang <wangjia@ultrarisc.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20260429-ultrarisc-serial-v7-2-e475cce9e274@ultrarisc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Move the DW_UART_* register offsets and CPR bit/field definitions from
8250_dwlib.c into 8250_dwlib.h so they can be shared by 8250_dw and
8250_dwlib users.
Add an include guard for 8250_dwlib.h.
Signed-off-by: Jia Wang <wangjia@ultrarisc.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20260429-ultrarisc-serial-v7-1-e475cce9e274@ultrarisc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Rather than using the UPF_CONS_FLOW bit of uart_port.flags to track
the user configuration of console flow control, use the newly added
uart_port.cons_flow (via its getter/setter functions).
A coccinelle script was used to perform the search/replace.
Note1: The sh-sci driver is blindly copying platform data configuration
flags to uart_port.flags. Thus UPF_CONS_FLOW could get set for
uart_port.flags. A follow-up commit will address this.
Note2: The samsung_tty driver is using UPF_CONS_FLOW as a platform data
configuration flag. However, the driver explicitly checks for
this configuration flag and thus setting UPF_CONS_FLOW in
uart_port.flags is avoided.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://patch.msgid.link/20260506121606.5805-3-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver doesn't use the driver_data field, so drop the assigment
together with the then redundant zero assigment for .class and
.class_mask. Also drop the zero in the list terminator.
While at it also use PCI_VDEVICE() to allow dropping "PCI_VENDOR_ID_".
Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
Link: https://patch.msgid.link/20260505084749.2304121-2-u.kleine-koenig@baylibre.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
... and PCI device helpers.
The various struct pci_device_id were defined using a mixture of
initialization by position and by name. Some use the PCI device helpers
(like PCI_DEVICE and PCI_DEVICE_SUB) and others don't.
Consistently use named initializers, drop assignments of 0 by position
for .class and .class_mask and use the PCI device helpers. Also use
consistent line-breaks and positioning for opening and closing curly
braces.
The secret plan is to make struct pci_device_id::driver_data an
anonymous union (similar to
https://lore.kernel.org/all/cover.1776579304.git.u.kleine-koenig@baylibre.com/)
and that requires named initializers. But it's also a nice cleanup on
its own.
This patch doesn't change the compiled result; this was verified using
an allmodconfig with several things disabled that make reproducible
builds harder on x86 and arm64.
Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
Link: https://patch.msgid.link/20260428144033.1037617-2-u.kleine-koenig@baylibre.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The synclink_gt driver was marked as broken in commit 426263d5fb
("tty: synclink_gt: mark as BROKEN") in July 2023 because it had severe
structural problems and there had been no evidence of users since 2016.
Since then, no meaningful improvements have been made to the driver,
and it is unlikely that will ever happen due to the lack of interest.
Drop the driver and references to it in comments and documentation.
include/uapi/linux/synclink.h is also removed. The only use of this
header I have found is the linux-raw-sys Rust crate. It generates
bindings for all UAPI headers, but has a hardcoded list of headers and
ioctls, including this one, so that does not indicate that anyone is
using it. I have sent a pull request to remove the include and ioctl
definitions for this header (see the link below).
Link: https://github.com/sunfishcode/linux-raw-sys/pull/185
Signed-off-by: Ethan Nelson-Moore <enelsonmoore@gmail.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Link: https://patch.msgid.link/20260504031519.18877-1-enelsonmoore@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
My MIPS Alchemy systems generate the following warning during
probe of the 8250 driver:
WARNING: drivers/tty/serial/8250/8250_port.c:462 at set_io_from_upio+0xfc/0x124, CPU#0: swapper/0/1
Unsupported UART type 4
[...]
[<80521d40>] set_io_from_upio+0xfc/0x124
[<80521dfc>] serial8250_set_defaults+0x94/0xe0
[<80520fb4>] serial8250_register_8250_port+0x288/0x51c
[<805214ec>] serial8250_probe+0x160/0x1e8
[<8053b5f0>] platform_probe+0x64/0x90
The least invasive fix is to recognize UPIO_AU (type 4) in set_io_from_upio()
and do nothing, since all parameters have already been set up in
8250_rt288x.c::au_platform_setup().
Run-tested on Alchemy Au1300 platform.
Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
Link: https://patch.msgid.link/20260430135822.905035-1-manuel.lauss@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The GPIO_LINE_DIRECTION_* definitions have just recently been exposed to
gpio consumers.h by breaking them out in a separate defs.h file.
Use this to validate the gpio direction instead of the hard-coded literal.
Signed-off-by: Nikola Z. Ivanov <zlatistiv@gmail.com>
Link: https://patch.msgid.link/20260426214250.781151-1-zlatistiv@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add ACPI support to 8250_mtk driver. This makes it possible to
use UART on ARM-based desktops with EDK2 UEFI firmware.
Signed-off-by: Yenchia Chen <yenchia.chen@mediatek.com>
Signed-off-by: Zhiyong Tao <zhiyong.tao@mediatek.com>
Link: https://patch.msgid.link/20260423062345.2473300-2-zhiyong.tao@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Various names for Qualcomm as a company are used in user-visible config
options: QCOM, Qualcomm and Qualcomm Technologies. Switch to unified
"Qualcomm" so it will be easier for users to identify the options when
for example running menuconfig.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Link: https://patch.msgid.link/20260427070052.18097-2-krzysztof.kozlowski@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In C, bitfields are not necessarily safe to modify from multiple
threads without locking. Switch "of_node_reused" over to the "flags"
field so modifications are safe.
Cc: Johan Hovold <johan@kernel.org>
Acked-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Johan Hovold <johan@kernel.org>
Acked-by: Manivannan Sadhasivam <mani@kernel.org> # PCI_PWRCTRL
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://patch.msgid.link/20260406162231.v5.8.I806b8636cd3724f6cd1f5e199318ab8694472d90@changeid
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Here is the set of tty and serial driver changes for 7.1-rc1.
Not much here this cycle, biggest thing is the removal of an old driver
that never got any actual hardware support (esp32), and the second try
to moving the tty ports to their own workqueues (first try was in
7.0-rc1 but was reverted due to problems.)
Otherwise it's just a small set of driver updates and some vt modifier
key enhancements.
All have been in linux-next for a while with no reported issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial updates from Greg KH:
"Here is the set of tty and serial driver changes for 7.1-rc1.
Not much here this cycle, biggest thing is the removal of an old
driver that never got any actual hardware support (esp32), and the
second try to moving the tty ports to their own workqueues (first try
was in 7.0-rc1 but was reverted due to problems)
Otherwise it's just a small set of driver updates and some vt modifier
key enhancements.
All have been in linux-next for a while with no reported issues"
* tag 'tty-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (35 commits)
tty: serial: ip22zilog: Fix section mispatch warning
hvc/xen: Check console connection flag
serial: sh-sci: Add support for RZ/G3L RSCI
dt-bindings: serial: renesas,rsci: Document RZ/G3L SoC
tty: atmel_serial: update outdated reference to atmel_tasklet_func()
serial: xilinx_uartps: Drop unused include
serial: qcom-geni: drop stray newline format specifier
serial: 8250: loongson: Enable building on MIPS Loongson64
dt-bindings: serial: 8250: Add Loongson 3A4000 uart compatible
serial: 8250_fintek: Add support for F81214E
tty: tty_port: add workqueue to flip TTY buffer
vt: support ITU-T T.416 color subparameters
serial: qcom-geni: Fix RTS behavior with flow control
tty: serial: imx: keep dma request disabled before dma transfer setup
tty: serial: 8250: Add SystemBase Multi I/O cards
serial: pic32_uart: allow driver to be compiled on all architectures with COMPILE_TEST
serial: tegra: remove Kconfig dependency on APB DMA controller
dt-bindings: serial: amlogic,meson-uart: Add compatible string for A9
dt-bindings: serial: atmel,at91-usart: add microchip,lan9691-usart
serial: auart: check clk_enable() return in console write
...
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Merge tag 'for-linus-7.1-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen updates from Juergen Gross:
- fix an error path in drivers/xen/manage.c
- fix the Xen console driver solving a boot hangup when the console
backend isn't yet running
- comment fix in the Xen swiotlb driver
- hardening for Xen on Arm adding a more thorough validation
- cleanup of the Xen grant table code hiding suspend/resume code for
the case if CONFIG_HIBERNATE_CALLBACKS isn't defined
* tag 'for-linus-7.1-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/grant-table: guard gnttab_suspend/resume with CONFIG_HIBERNATE_CALLBACKS
hvc/xen: Check console connection flag
xen/swiotlb: fix stale reference to swiotlb_unmap_page()
xen/manage: unwind partial shutdown watcher setup on error
ARM: xen: validate hypervisor compatible before parsing its version
A major refactorization by Thomas Zimmermann from SUSE regarding handling of
console font data, addition of helpers for console font rotation and split into
individual components for glyphs, fonts and the overall fbcon state.
And there is the round of usual code cleanups and fixes:
Cleanups:
- atyfb: Remove unused fb_list [Geert Uytterhoeven]
- goldfishfb, wmt_ge_rops: use devm_platform_ioremap_resource() [Amin GATTOUT]
- matroxfb: Mark variable with __maybe_unused [Andy Shevchenko]
- omapfb: Add missing error check for clk_get() [Chen Ni]
- tdfxfb: Make the VGA register initialisation a bit more obvious [Daniel Palmer]
- macfb: Replace deprecated strcpy with strscpy [Thorsten Blum]
Fixes:
- tdfxfb, udlfb: avoid divide-by-zero on FBIOPUT_VSCREENINFO [Greg Kroah-Hartman]
- omap2: fix inconsistent lock returns in omapfb_mmap [Hongling Zeng]
- viafb: check ioremap return value in viafb_lcd_get_mobile_state [Wang Jun]
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Merge tag 'fbdev-for-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev
Pull fbdev updates from Helge Deller:
"A major refactorization by Thomas Zimmermann from SUSE regarding
handling of console font data, addition of helpers for console font
rotation and split into individual components for glyphs, fonts and
the overall fbcon state.
And there is the round of usual code cleanups and fixes:
Cleanups:
- atyfb: Remove unused fb_list (Geert Uytterhoeven)
- goldfishfb, wmt_ge_rops: use devm_platform_ioremap_resource() (Amin GATTOUT)
- matroxfb: Mark variable with __maybe_unused (Andy Shevchenko)
- omapfb: Add missing error check for clk_get() (Chen Ni)
- tdfxfb: Make the VGA register initialisation a bit more obvious (Daniel Palmer)
- macfb: Replace deprecated strcpy with strscpy (Thorsten Blum)
Fixes:
- tdfxfb, udlfb: avoid divide-by-zero on FBIOPUT_VSCREENINFO (Greg Kroah-Hartman)
- omap2: fix inconsistent lock returns in omapfb_mmap (Hongling Zeng)
- viafb: check ioremap return value in viafb_lcd_get_mobile_state (Wang Jun)"
* tag 'fbdev-for-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev: (40 commits)
fbdev: udlfb: avoid divide-by-zero on FBIOPUT_VSCREENINFO
fbdev: tdfxfb: avoid divide-by-zero on FBIOPUT_VSCREENINFO
fbdev: omap2: fix inconsistent lock returns in omapfb_mmap
MAINTAINERS: Add dedicated entry for fbcon
fbcon: Put font-rotation state into separate struct
fbcon: Fill cursor mask in helper function
lib/fonts: Implement font rotation
lib/fonts: Refactor glyph-rotation helpers
lib/fonts: Refactor glyph-pattern helpers
lib/fonts: Implement glyph rotation
lib/fonts: Clean up Makefile
lib/fonts: Provide helpers for calculating glyph pitch and size
vt: Implement helpers for struct vc_font in source file
fbcon: Avoid OOB font access if console rotation fails
fbdev: atyfb: Remove unused fb_list
fbdev: matroxfb: Mark variable with __maybe_unused to avoid W=1 build break
fbdev: update help text for CONFIG_FB_NVIDIA
fbdev: omapfb: Add missing error check for clk_get()
fbdev: viafb: check ioremap return value in viafb_lcd_get_mobile_state
lib/fonts: Remove internal symbols and macros from public header file
...
- add support for the PCIe M.2 Key E connectors in pwrseq-pcie-m2
- describe PCIe M.2 Mechanical Key E connectors in DT bindings
- add serdev helpers for looking up devices by OF nodes
- minor serdev core rework to enable support for PCIe M.2 Key E connectors
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Merge tag 'pwrseq-updates-for-v7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux
Pull power sequencing updates from Bartosz Golaszewski:
"For this release we have an extension of the pwrseq-pcie-m2 driver
with support for PCIe M.2 Key E connectors.
The rest of the commits fulfill a supporting role: document the
hardware in DT bindings, provide required serdev helpers (this has
been provided in an immutable branch to Rob Herring so you may see it
in his PR as well) and is followed up by some Kconfig fixes from Arnd.
Summary:
- add support for the PCIe M.2 Key E connectors in pwrseq-pcie-m2
- describe PCIe M.2 Mechanical Key E connectors in DT bindings
- add serdev helpers for looking up devices by OF nodes
- minor serdev core rework to enable support for PCIe M.2 Key E
connectors"
* tag 'pwrseq-updates-for-v7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
power: sequencing: pcie-m2: add SERIAL_DEV_BUS dependency
power: sequencing: pcie-m2: enforce PCI and OF dependencies
power: sequencing: pcie-m2: Create serdev device for WCN7850 bluetooth
power: sequencing: pcie-m2: Add support for PCIe M.2 Key E connectors
dt-bindings: connector: Add PCIe M.2 Mechanical Key E connector
dt-bindings: serial: Document the graph port
serdev: Do not return -ENODEV from of_serdev_register_devices() if external connector is used
serdev: Add an API to find the serdev controller associated with the devicetree node
serdev: Convert to_serdev_*() helpers to macros and use container_of_const()
When the console out buffer is filled, __write_console() will return 0
as it cannot send any data. domU_write_console() will then spin in
`while (len)` as len doesn't decrement until xenconsoled attaches. This
would block a domU and nullify the parallelism of Hyperlaunch until dom0
userspace starts xenconsoled, which empties the buffer.
Xen 4.21 added a connection field to the xen console page. This is set
to XENCONSOLE_DISCONNECTED (1) when a domain is built, and xenconsoled
will set it to XENCONSOLE_CONNECTED (0) when it connects.
Update the hvc_xen driver to check the field. When the field is
disconnected, drop the write with -ENOTCONN. We only drop the write
when the field is XENCONSOLE_DISCONNECTED (1) to try for maximum
compatibility. The Xen toolstack has historically zero initialized the
console, so it should see XENCONSOLE_CONNECTED (0) by default. If an
implemenation used uninitialized memory, only checking for
XENCONSOLE_DISCONNECTED could have the lowest chance of not connecting.
This lets the hyperlaunched domU boot without stalling. Once dom0
starts xenconsoled, xl console can be used to access the domU's hvc0.
Paritally sync console.h from xen.git to bring in the new field.
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Jason Andryuk <jason.andryuk@amd.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Message-ID: <20260318235326.14568-1-jason.andryuk@amd.com>
Implement pitch and size calculation for a single font glyph in the
new helpers font_glyph_pitch() and font_glyph_size(). Replace the
instances where the calculations are open-coded.
Note that in the case of fbcon console rotation, the parameters for
a glyph's width and height might be reversed. This is intentional.
v2:
- fix typos in commit message
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Move the helpers vc_font_pitch() and vc_font_size() from the VT
header file into source file. They are not called very often, so
there's no benefit in keeping them in the headers. Also avoids
including <linux/math.h> from the header.
v2:
- fix typo in commit description
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Helge Deller <deller@gmx.de>
If an external connector like M.2 is connected to the serdev controller
in DT, then the serdev devices may be created dynamically by the connector
driver. So do not return -ENODEV from of_serdev_register_devices() if the
static nodes are not found and the graph node is used.
Tested-by: Hans de Goede <johannes.goede@oss.qualcomm.com> # ThinkPad T14s gen6 (arm64)
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20260326-pci-m2-e-v7-3-43324a7866e6@oss.qualcomm.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Instead of discarding the saved unicode buffer when the console was
resized while in the alternate screen, resize it to the current
dimensions using vc_uniscr_copy_area() to preserve its content. This
properly restores the unicode screen on alt screen exit rather than
lazily rebuilding it from a lossy reverse glyph translation.
On allocation failure the stale buffer is freed and vc_uni_lines is
set to NULL so it gets lazily rebuilt via vc_uniscr_check() when next
needed.
Fixes: 40014493ce ("vt: discard stale unicode buffer on alt screen exit after resize")
Cc: stable <stable@kernel.org>
Signed-off-by: Nicolas Pitre <nico@fluxnic.net>
Link: https://patch.msgid.link/3nsr334n-079q-125n-7807-n4nq818758ns@syhkavp.arg
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When enter_alt_screen() saves vc_uni_lines into vc_saved_uni_lines and
sets vc_uni_lines to NULL, a subsequent console resize via vc_do_resize()
skips reallocating the unicode buffer because vc_uni_lines is NULL.
However, vc_saved_uni_lines still points to the old buffer allocated for
the original dimensions.
When leave_alt_screen() later restores vc_saved_uni_lines, the buffer
dimensions no longer match vc_rows/vc_cols. Any operation that iterates
over the unicode buffer using the current dimensions (e.g. csi_J clearing
the screen) will access memory out of bounds, causing a kernel oops:
BUG: unable to handle page fault for address: 0x0000002000000020
RIP: 0010:csi_J+0x133/0x2d0
The faulting address 0x0000002000000020 is two adjacent u32 space
characters (0x20) interpreted as a pointer, read from the row data area
past the end of the 25-entry pointer array in a buffer allocated for
80x25 but accessed with 240x67 dimensions.
Fix this by checking whether the console dimensions changed while in the
alternate screen. If they did, free the stale saved buffer instead of
restoring it. The unicode screen will be lazily rebuilt via
vc_uniscr_check() when next needed.
Fixes: 5eb608319b ("vt: save/restore unicode screen buffer for alternate screen")
Cc: stable <stable@kernel.org>
Tested-by: Liav Mordouch <liavmordouch@gmail.com>
Signed-off-by: Liav Mordouch <liavmordouch@gmail.com>
Reviewed-by: Nicolas Pitre <nico@fluxnic.net>
Link: https://patch.msgid.link/20260327170204.29706-1-liavmordouch@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When the console out buffer is filled, __write_console() will return 0
as it cannot send any data. domU_write_console() will then spin in
`while (len)` as len doesn't decrement until xenconsoled attaches. This
would block a domU and nullify the parallelism of Hyperlaunch until dom0
userspace starts xenconsoled, which empties the buffer.
Xen 4.21 added a connection field to the xen console page. This is set
to XENCONSOLE_DISCONNECTED (1) when a domain is built, and xenconsoled
will set it to XENCONSOLE_CONNECTED (0) when it connects.
Update the hvc_xen driver to check the field. When the field is
disconnected, drop the write with -ENOTCONN. We only drop the write
when the field is XENCONSOLE_DISCONNECTED (1) to try for maximum
compatibility. The Xen toolstack has historically zero initialized the
console, so it should see XENCONSOLE_CONNECTED (0) by default. If an
implemenation used uninitialized memory, only checking for
XENCONSOLE_DISCONNECTED could have the lowest chance of not connecting.
This lets the hyperlaunched domU boot without stalling. Once dom0
starts xenconsoled, xl console can be used to access the domU's hvc0.
Paritally sync console.h from xen.git to bring in the new field.
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Jason Andryuk <jason.andryuk@amd.com>
Link: https://patch.msgid.link/20260318235326.14568-1-jason.andryuk@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add support for RZ/G3L RSCI. The RSCI IP found on the RZ/G3L SoC is
similar to RZ/G3E, but it has 3 clocks (2 module clocks + 1 external
clock) instead of 6 clocks (5 module clocks + 1 external clock) on the
RZ/G3E. Both RZ/G3L and RZ/G3E have a 32-bit FIFO, but RZ/G3L has a
single TCLK with internal dividers, whereas the RZ/G3E has explicit
clocks for TCLK and its dividers. Add a new port type
RSCI_PORT_SCIF32_SINGLE_TCLK to handle this clock difference.
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20260312082708.98835-3-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The modem-status comparison that used irq_status_prev was
moved from atmel_tasklet_func() into atmel_handle_status() in
commit d033e82db9 ("tty/serial: at91: handle IRQ status
more safely"). Update the comment accordingly.
Assisted-by: unnamed:deepseek-v3.2 coccinelle
Signed-off-by: Kexin Sun <kexinsun@smail.nju.edu.cn>
Link: https://patch.msgid.link/20260324024857.3244-1-kexinsun@smail.nju.edu.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Drop the newline character from the middle of the printk message.
This avoids breaking the message into two lines unnecessarily.
Signed-off-by: Kathiravan Thirumoorthy <kathiravan.thirumoorthy@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Link: https://patch.msgid.link/20260319-drop_stray_n-v1-1-37fb619538bb@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Loongson 3A4000 is a MIPS-based Loongson64 CPU which also supports
8250_loongson (loongson-uart).
Enable building on MIPS Loongson64 so that Loongson 3A4000 can benefit
from it.
Signed-off-by: Rong Zhang <rongrong@oss.cipunited.com>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Link: https://patch.msgid.link/20260315184301.412844-3-rongrong@oss.cipunited.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The F81214E is a LPC/eSPI to 2 UART Super I/O chip.
Functionally, it is the same as the F81216E. The only difference
is that the F81216E has 4 UART ports, whereas the F81214E has 2
UART ports.
Signed-off-by: Ravi Rama <ravi.rama@nexthop.ai>
Link: https://patch.msgid.link/20260313194731.2671-1-ravi.rama@nexthop.ai
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge 7.0-rc5 into tty-next
We need the tty/serial fixes in here as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The alternate screen support added by commit 23743ba647 ("vt: add
support for smput/rmput escape codes") only saves and restores the
regular screen buffer (vc_origin), but completely ignores the corresponding
unicode screen buffer (vc_uni_lines) creating a messed-up display.
Add vc_saved_uni_lines to save the unicode screen buffer when entering
the alternate screen, and restore it when leaving. Also ensure proper
cleanup in reset_terminal() and vc_deallocate().
Fixes: 23743ba647 ("vt: add support for smput/rmput escape codes")
Cc: stable <stable@kernel.org>
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Link: https://patch.msgid.link/5o2p6qp3-91pq-0p17-or02-1oors4417ns7@onlyvoer.pbz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
DW UART cannot write to LCR, DLL, and DLH while BUSY is asserted.
Existance of BUSY depends on uart_16550_compatible, if UART HW is
configured with it those registers can always be written.
There currently is dw8250_force_idle() which attempts to achieve
non-BUSY state by disabling FIFO, however, the solution is unreliable
when Rx keeps getting more and more characters.
Create a sequence of operations that ensures UART cannot keep BUSY
asserted indefinitely. The new sequence relies on enabling loopback mode
temporarily to prevent incoming Rx characters keeping UART BUSY.
Ensure no Tx in ongoing while the UART is switches into the loopback
mode (requires exporting serial8250_fifo_wait_for_lsr_thre() and adding
DMA Tx pause/resume functions).
According to tests performed by Adriana Nicolae <adriana@arista.com>,
simply disabling FIFO or clearing FIFOs only once does not always
ensure BUSY is deasserted but up to two tries may be needed. This could
be related to ongoing Rx of a character (a guess, not known for sure).
Therefore, retry FIFO clearing a few times (retry limit 4 is arbitrary
number but using, e.g., p->fifosize seems overly large). Tests
performed by others did not exhibit similar challenge but it does not
seem harmful to leave the FIFO clearing loop in place for all DW UARTs
with BUSY functionality.
Use the new dw8250_idle_enter/exit() to do divisor writes and LCR
writes. In case of plain LCR writes, opportunistically try to update
LCR first and only invoke dw8250_idle_enter() if the write did not
succeed (it has been observed that in practice most LCR writes do
succeed without complications).
This issue was first reported by qianfan Zhao who put lots of debugging
effort into understanding the solution space.
Fixes: c49436b657 ("serial: 8250_dw: Improve unwritable LCR workaround")
Fixes: 7d4008ebb1 ("tty: add a DesignWare 8250 driver")
Cc: stable <stable@kernel.org>
Reported-by: qianfan Zhao <qianfanguijin@163.com>
Link: https://lore.kernel.org/linux-serial/289bb78a-7509-1c5c-2923-a04ed3b6487d@163.com/
Reported-by: Adriana Nicolae <adriana@arista.com>
Link: https://lore.kernel.org/linux-serial/20250819182322.3451959-1-adriana@arista.com/
Reported-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Murthy, Shanth <shanth.murthy@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20260203171049.4353-8-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When DW UART is !uart_16550_compatible, it can indicate BUSY at any
point (when under constant Rx pressure) unless a complex sequence of
steps is performed. Any LCR write can run a foul with the condition
that prevents writing LCR while the UART is BUSY, which triggers
BUSY_DETECT interrupt that seems unmaskable using IER bits.
Normal flow is that dw8250_handle_irq() handles BUSY_DETECT condition
by reading USR register. This BUSY feature, however, breaks the
assumptions made in serial8250_do_shutdown(), which runs
synchronize_irq() after clearing IER and assumes no interrupts can
occur after that point but then proceeds to update LCR, which on DW
UART can trigger an interrupt.
If serial8250_do_shutdown() releases the interrupt handler before the
handler has run and processed the BUSY_DETECT condition by read the USR
register, the IRQ is not deasserted resulting in interrupt storm that
triggers "irq x: nobody cared" warning leading to disabling the IRQ.
Add late synchronize_irq() into serial8250_do_shutdown() to ensure
BUSY_DETECT from DW UART is handled before port's interrupt handler is
released. Alternative would be to add DW UART specific shutdown
function but it would mostly duplicate the generic code and the extra
synchronize_irq() seems pretty harmless in serial8250_do_shutdown().
Fixes: 7d4008ebb1 ("tty: add a DesignWare 8250 driver")
Cc: stable <stable@kernel.org>
Reported-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Murthy, Shanth <shanth.murthy@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20260203171049.4353-7-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
INTC10EE UART can end up into an interrupt storm where it reports
IIR_NO_INT (0x1). If the storm happens during active UART operation, it
is promptly stopped by IIR value change due to Rx or Tx events.
However, when there is no activity, either due to idle serial line or
due to specific circumstances such as during shutdown that writes
IER=0, there is nothing to stop the storm.
During shutdown the storm is particularly problematic because
serial8250_do_shutdown() calls synchronize_irq() that will hang in
waiting for the storm to finish which never happens.
This problem can also result in triggering a warning:
irq 45: nobody cared (try booting with the "irqpoll" option)
[...snip...]
handlers:
serial8250_interrupt
Disabling IRQ #45
Normal means to reset interrupt status by reading LSR, MSR, USR, or RX
register do not result in the UART deasserting the IRQ.
Add a quirk to INTC10EE UARTs to enable Tx interrupts if UART's Tx is
currently empty and inactive. Rework IIR_NO_INT to keep track of the
number of consecutive IIR_NO_INT, and on fourth one perform the quirk.
Enabling Tx interrupts should change IIR value from IIR_NO_INT to
IIR_THRI which has been observed to stop the storm.
Fixes: e92fad0249 ("serial: 8250_dw: Add ACPI ID for Granite Rapids-D UART")
Cc: stable <stable@kernel.org>
Reported-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Murthy, Shanth <shanth.murthy@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20260203171049.4353-6-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dw8250_handle_irq() takes port's lock multiple times with no good
reason to release it in between and calls serial8250_handle_irq()
that also takes port's lock.
Take port's lock only once in dw8250_handle_irq() and use
serial8250_handle_irq_locked() to avoid releasing port's lock in
between.
As IIR_NO_INT check in serial8250_handle_irq() was outside of port's
lock, it has to be done already in dw8250_handle_irq().
DW UART can, in addition to IIR_NO_INT, report BUSY_DETECT (0x7) which
collided with the IIR_NO_INT (0x1) check in serial8250_handle_irq()
(because & is used instead of ==) meaning that no other work is done by
serial8250_handle_irq() during an BUSY_DETECT interrupt.
This allows reorganizing code in dw8250_handle_irq() to do both
IIR_NO_INT and BUSY_DETECT handling right at the start simplifying
the logic.
Tested-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Murthy, Shanth <shanth.murthy@intel.com>
Cc: stable <stable@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20260203171049.4353-5-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
8250_port exports serial8250_handle_irq() to HW specific 8250 drivers.
It takes port's lock within but a HW specific 8250 driver may want to
take port's lock itself, do something, and then call the generic
handler in 8250_port but to do that, the caller has to release port's
lock for no good reason.
Introduce serial8250_handle_irq_locked() which a HW specific driver can
call while already holding port's lock.
As this is new export, put it straight into a namespace (where all 8250
exports should eventually be moved).
Tested-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Murthy, Shanth <shanth.murthy@intel.com>
Cc: stable <stable@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20260203171049.4353-4-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When DW UART is configured with BUSY flag, LCR writes may not always
succeed which can make any LCR write complex and very expensive.
Performing write directly can trigger IRQ and the driver has to perform
complex and distruptive sequence while retrying the write.
Therefore, it's better to avoid doing LCR write that would not change
the value of the LCR register. Add LCR write avoidance code into the
8250_dw driver's .serial_out() functions.
Reported-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Murthy, Shanth <shanth.murthy@intel.com>
Cc: stable <stable@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20260203171049.4353-3-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The 8250_dw driver needs to potentially perform very complex operations
during LCR writes because its BUSY handling prevents updates to LCR
while UART is BUSY (which is not fully under our control without those
complex operations). Thus, LCR writes should occur under port's lock.
Move LCR write under port's lock in serial8250_do_shutdown(). Also
split the LCR RMW so that the logic is on a separate line for clarity.
Reported-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Murthy, Shanth <shanth.murthy@intel.com>
Cc: stable <stable@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20260203171049.4353-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
