Some UARTs require driver-specific handling for break signaling, which
cannot be expressed by the generic 8250 break implementation alone.
Add an optional uart_port break_ctl callback and route
serial8250_break_ctl() through it when provided. Rename the existing
8250 implementation to serial8250_do_break_ctl() and export it so
low-level drivers can reuse the default 8250 behavior when appropriate.
Signed-off-by: Crescent Hsieh <crescentcy.hsieh@moxa.com>
Link: https://patch.msgid.link/20260731074820.735619-11-crescentcy.hsieh@moxa.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Moxa PCIe multiport serial boards support switching the serial interface
mode between RS232, RS422, RS485-2W, and RS485-4W via on-board control
registers.
Implement an rs485_config() callback and map TIOCSRS485 requests to the
corresponding hardware modes using serial_rs485 flags:
- RS232 = (no flags set)
- RS422 = SER_RS485_ENABLED | SER_RS485_MODE_RS422
- RS485_2W (half-duplex) = SER_RS485_ENABLED
- RS485_4W (full-duplex) = SER_RS485_ENABLED | SER_RS485_RX_DURING_TX
This allows users to reconfigure the serial mode at runtime via ioctl().
Signed-off-by: Crescent Hsieh <crescentcy.hsieh@moxa.com>
Link: https://patch.msgid.link/20260731074820.735619-10-crescentcy.hsieh@moxa.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The MUEx50 UART provides a memory-mapped TX FIFO data window along with
a TX FIFO level counter.
Fill the TX FIFO in bulk via the MMIO FIFO window based on available
FIFO space, using uart_port_tx_limited() for the common serial-core TX
handling.
Signed-off-by: Crescent Hsieh <crescentcy.hsieh@moxa.com>
Link: https://patch.msgid.link/20260731074820.735619-9-crescentcy.hsieh@moxa.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The MUEx50 UART provides a memory-mapped RX FIFO data window along with
an RX FIFO byte counter.
When no break or error conditions are present, read received data in
bulk via the MMIO FIFO window and push it to the tty layer in one
operation. Fall back to the generic 8250 RX path for break and error
handling.
Signed-off-by: Crescent Hsieh <crescentcy.hsieh@moxa.com>
Link: https://patch.msgid.link/20260731074820.735619-8-crescentcy.hsieh@moxa.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a mxpcie-specific handle_irq() implementation for Moxa PCIe serial
ports.
This keeps the interrupt handling self-contained in the driver and
provides a hook point for MUEx50-specific RX/TX paths added in subsequent
patches. The handler processes RX, updates modem status, and handles TX
when THRE is asserted.
Signed-off-by: Crescent Hsieh <crescentcy.hsieh@moxa.com>
Link: https://patch.msgid.link/20260731074820.735619-7-crescentcy.hsieh@moxa.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The MUEx50 UART can handle in-band software flow control (XON/XOFF)
directly in hardware.
Program the on-chip XON/XOFF characters from termios settings and enable
the corresponding MUEx50 flow control modes when IXON or IXOFF is
requested. Provide throttle and unthrottle callbacks so RX can be
stopped and resumed cleanly.
Signed-off-by: Crescent Hsieh <crescentcy.hsieh@moxa.com>
Link: https://patch.msgid.link/20260731074820.735619-6-crescentcy.hsieh@moxa.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The MUEx50 UART supports automatic RTS/CTS flow control via the enhanced
feature register.
Implement a mxpcie-specific set_termios() callback that enables MUEx50
auto-RTS/auto-CTS when CRTSCTS is requested and disables it otherwise.
Keep the 8250 port status flags in sync with the hardware configuration.
Signed-off-by: Crescent Hsieh <crescentcy.hsieh@moxa.com>
Link: https://patch.msgid.link/20260731074820.735619-5-crescentcy.hsieh@moxa.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The MUEx50 UART provides an enhanced register set and programmable FIFO
trigger levels for RX, TX, and flow control.
Enable enhanced mode during port startup and program the MUEx50 FIFO
trigger registers according to the configured port settings. Clear the
programmed state again during shutdown to restore the default UART
configuration.
The TX FIFO write pointer and read pointer are driven by different
clocks. Clear the FIFOs repeatedly during startup so both pointers are
reset before programming the trigger levels.
Signed-off-by: Crescent Hsieh <crescentcy.hsieh@moxa.com>
Link: https://patch.msgid.link/20260731074820.735619-4-crescentcy.hsieh@moxa.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a new 8250 port type for the Moxa MUEx50 UART and describe its basic
FIFO size and trigger characteristics in the 8250 port configuration
table.
The 8250_mxpcie driver sets UPF_FIXED_TYPE and uses PORT_MUEX50 so that
the generic 8250 core applies the correct defaults.
Signed-off-by: Crescent Hsieh <crescentcy.hsieh@moxa.com>
Link: https://patch.msgid.link/20260731074820.735619-3-crescentcy.hsieh@moxa.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The Moxa PCIe multiport serial boards are currently handled as part of
8250_pci.c. In preparation for adding Moxa-specific UART features and
optimizations, move the Moxa PCIe implementation into a dedicated
driver.
This introduces drivers/tty/serial/8250/8250_mxpcie.c and wires it up
via Kconfig and Makefile, while preserving the existing probe flow and
device IDs.
This change was suggested during earlier reviews by Andy Shevchenko [1][2].
No functional change intended.
Link: https://lore.kernel.org/all/ZmQovC6TbDpTb3c8@surfacebook.localdomain/ [1]
Link: https://lore.kernel.org/all/CAHp75VeDsVt0GQYUFxLM+obfmqXBPa3hM3YMsFbc26uzWZG-SQ@mail.gmail.com/ [2]
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Crescent Hsieh <crescentcy.hsieh@moxa.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://patch.msgid.link/20260731074820.735619-2-crescentcy.hsieh@moxa.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver implements its own helper to select the performance level
corresponding to a requested baud rate. The helper duplicates
functionality already provided by geni_se_set_perf_level() in the GENI
core.
Replace the local implementation with the common helper and remove the
associated duplicate definitions and code. This consolidates
performance-level management in the GENI framework and reduces driver
specific code.
Signed-off-by: Praveen Talari <praveen.talari@oss.qualcomm.com>
Link: https://patch.msgid.link/20260801-reuse_common_geni_framework_helpers-v2-3-13753256ef71@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To manage GENI serial engine resources during runtime power
management, drivers currently need to call functions for ICC, clock,
and SE resource operations in both suspend and resume paths, resulting
in code duplication across drivers.
The new geni_se_resources_activate() and geni_se_resources_deactivate()
helper APIs addresses this issue by providing a streamlined method to
enable or disable all resources based, thereby eliminating redundancy
across drivers.
Signed-off-by: Praveen Talari <praveen.talari@oss.qualcomm.com>
Link: https://patch.msgid.link/20260801-reuse_common_geni_framework_helpers-v2-2-13753256ef71@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The UART driver maintains local helpers for resource and power-domain
initialisation that duplicate functionality already provided by the common
GENI framework.
Replace the driver-specific implementations with geni_se_resources_init()
and geni_se_domain_attach(), and use the power-domain list stored in
struct geni_se. This reduces code duplication and centralises GENI resource
management without functional changes.
Signed-off-by: Praveen Talari <praveen.talari@oss.qualcomm.com>
Link: https://patch.msgid.link/20260801-reuse_common_geni_framework_helpers-v2-1-13753256ef71@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pl011_console_write_atomic() runs from nbcon atomic context, where
sleeping is not allowed. It calls clk_enable(), which takes the common-clk
enable_lock. Under PREEMPT_RT that is a sleeping lock:
clk_enable_lock() first tries spin_trylock_irqsave(), but on contention
falls back to spin_lock_irqsave(). Therefore, an atomic-context printk on
an RT kernel with a clk-backed pl011 can trip:
BUG: sleeping function called from invalid context at spinlock_rt.c:48
__might_resched from rt_spin_lock
rt_spin_lock from clk_enable_lock
clk_enable_lock from clk_enable
clk_enable from pl011_console_write_atomic
... from vprintk_emit
This was found and reproduced on PREEMPT_RT. Arm32 and arm64 DT SoCs are
affected; arm64 SBSA/ACPI has no clk, so clk_enable(NULL) short-circuits
before the lock. In addition, write_atomic() may be invoked from NMI
context and is documented to avoid locking. Removing clk_enable() from
the callback also avoids a potentially unsafe NMI acquisition of the
common-clock enable_lock.
An nbcon atomic-capable console must be printable from any context, so
the clock cannot be gated between writes. Enable the clock while the
console is available for output: use clk_prepare_enable() in
pl011_console_setup(), release it via clk_disable_unprepare() in the
console .exit() callback, and drop the per-write clk_enable()/clk_disable()
pairs from write_atomic() and write_thread().
When printk suspends consoles, drop the reference after
uart_suspend_port() stops console access and restore it before
uart_resume_port() -- but only if suspend actually marked the port
suspended (a wake-capable tty stays running and must keep its clock), and
keep it when console_suspend_enabled is false so no_console_suspend works.
The active power cost of keeping the clock enabled is platform-dependent:
none where the UART clock is a fixed always-on oscillator, real where it
is a gateable clock branch, which then cannot be gated (nor possibly can
its parent clocks) while the console is available for output. When serial
core actually suspends the port, the reference is released so the clock
provider can gate the clock tree.
Fixes: 2eb2608618 ("serial: amba-pl011: Implement nbcon console")
Suggested-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/all/8733xeaxix.fsf@jogness.linutronix.de/
Assisted-by: Claude:claude-fable-5
Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com>
Link: https://patch.msgid.link/20260724213348.77418-3-kmehltretter@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pl011_console_setup() calls clk_prepare() on the UART clock, but the
console provides no matching teardown, so the clock is never unprepared
when the console is unregistered -- via the sysfs "console" attribute or
a driver unbind. Each re-registration prepares the clock again, leaking
one prepare reference per cycle.
Even where preparing the clock has no hardware effect, the stale
reference leaves the clock framework's prepare count unbalanced. For
providers with prepare/unprepare operations or runtime-PM integration,
it may also retain resources after the console is unregistered.
Add a console .exit() callback that clk_unprepare()s the clock,
balancing the clk_prepare() in pl011_console_setup().
Fixes: 4b4851c65d ("clk: amba-pl011: convert to clk_prepare()/clk_unprepare()")
Assisted-by: Claude:claude-fable-5
Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com>
Link: https://patch.msgid.link/20260724213348.77418-2-kmehltretter@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The Genio board DTs provide serial aliases for all enabled UARTs, but
the MTK 8250 driver still registered every port with the default line
number. If uart0 deferred and another UART probed first, the 8250 core
could still assign ttyS0 to the wrong port despite the DT aliases.
Read the serial alias during OF probe and seed uart.port.line before
registering the port so the 8250 core reserves the requested ttyS slot.
Signed-off-by: Carlo Caione <ccaione@baylibre.com>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Link: https://patch.msgid.link/20260727-ccaione-genio-serial-aliases-v2-2-0f2ae41a8e89@baylibre.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dmaengine_terminate_all() does not wait for a running callback, so the TX
callback can still touch the TX buffer after it is freed. The RX poll
timer reads the RX buffers without the port lock.
Switch to dmaengine_terminate_sync() and delete the RX timer before
freeing the buffers.
Fixes: ead76f329f ("ARM: 6763/1: pl011: add optional RX DMA to PL011 v2")
Cc: stable <stable@kernel.org>
Assisted-by: Codex:gpt-5.6
Signed-off-by: Fan Wu <fanwu01@zju.edu.cn>
Link: https://patch.msgid.link/20260731085915.326775-4-fanwu01@zju.edu.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The RS485 trigger hrtimers are embedded in the devm-managed port and can
fire after it is freed. The IRQ handler can arm a timer, so free the IRQ
first and then cancel both timers.
Complete the RS485 stop without arming a timer, and cancel the timers
in remove() for the suspend-then-unbind path, where shutdown is not
called.
This issue was found by an in-house static analysis tool.
Fixes: 2c1fd53af2 ("serial: amba-pl011: Fix RTS handling in RS485 mode")
Cc: stable <stable@kernel.org>
Assisted-by: Codex:gpt-5.6
Signed-off-by: Fan Wu <fanwu01@zju.edu.cn>
Link: https://patch.msgid.link/20260731085915.326775-3-fanwu01@zju.edu.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The RS485 stop hrtimer is used both to drain the transmitter and to wait
out delay_rts_after_send. The callback cannot tell the two apart, so it
restarts the post-send delay on every expiry and the timer never stops.
Add a WAIT_AFTER_SEND_DELAY state so its expiry ends the stop sequence
instead of restarting the delay.
Fixes: 2c1fd53af2 ("serial: amba-pl011: Fix RTS handling in RS485 mode")
Cc: stable <stable@kernel.org>
Assisted-by: Codex:gpt-5.6
Signed-off-by: Fan Wu <fanwu01@zju.edu.cn>
Link: https://patch.msgid.link/20260731085915.326775-2-fanwu01@zju.edu.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
KDSKBMETA modifies keyboard meta mode but lacks the !perm check that all
other keyboard setter ioctls in vt_k_ioctl() enforce, allowing a process
to change meta mode on a non-controlling console without authorization.
Assisted-by: AISLE:Snapshot
Cc: stable <stable@kernel.org>
Signed-off-by: Joshua Rogers <linux@joshua.hu>
Link: https://patch.msgid.link/20260731-tty-vt-stuff-v1-2-be99b9da8e30@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kbd_keycode() reads vc->port.tty without acquiring a tty reference,
racing against con_shutdown() which clears port.tty under a different
lock. Use tty_port_tty_get()/tty_kref_put() to hold a proper reference
for the duration the tty pointer is needed.
Assisted-by: AISLE:Snapshot
Signed-off-by: Joshua Rogers <linux@joshua.hu>
Cc: stable <stable@kernel.org>
Link: https://patch.msgid.link/20260731-tty-vt-stuff-v1-1-be99b9da8e30@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The NXP LPC32xx UART (PORT_LPC3220) can latch an RX character-timeout
interrupt while the RX FIFO is empty: IIR reports UART_IIR_RX_TIMEOUT
(0x0c) but LSR.DR is clear. A character timeout is only cleared by
reading RHR, but serial8250_rx_chars() reads RHR only when LSR.DR is
set, so nothing ever clears the condition. The interrupt is
level-triggered and re-fires immediately, so on a single-core ARM926
the resulting interrupt storm livelocks the CPU.
It is reproducible when userspace repeatedly opens the front-panel port
(ttyS1): serial8250_do_set_termios() re-enables interrupts on unlock and
the handler then spins forever with iir=0xcc lsr=0x60 ier=0x05, tripping
the soft-lockup detector in serial8250_handle_irq_locked().
LPC32xx has no dedicated 8250 glue driver, it's driven by the generic
8250_of. Add a hardware specific handle_irq for PORT_LPC3220, wired up
in of_platform_serial_setup() the same way fsl8250_handle_irq is
installed. The handler follows dw8250_handle_irq(): on an RX timeout
with an empty FIFO (LSR.DR and LSR.BI clear) it does one throwaway RHR
read to clear the condition, then calls serial8250_handle_irq_locked().
No real received data is ever discarded, and it is a no-op on healthy
UARTs which never report a timeout with DR clear.
This is the same class of bug already worked around in other 8250 drivers;
see commit 424d79183a ("serial: 8250_dw: Avoid "too much work" from bogus rx timeout interrupt")
which reports the identical iir=0xcc/lsr=0x60. See also
UART_RX_TIMEOUT_QUIRK in 8250_omap, and the note in 8250_bcm7271.
Cc: stable <stable@kernel.org>
Assisted-by: Claude:Opus4.8
Signed-off-by: Ryan Wilbur <rwilbur633@gmail.com>
Link: https://patch.msgid.link/20260730193920.28954-1-rwilbur633@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The last mentions of this driver on local Linux and telco support forums
date back to 2011. This does not prove that no users remain, but the
likelihood is too low to justify continuing to carry the driver in the
kernel.
The maintainer agreed that the driver should be removed and noted that it
is simple enough to build as an external module if a user resurfaces [1].
Remove the driver along with its Kconfig, defconfig, build and MAINTAINERS
entries.
[1] https://lore.kernel.org/linux-serial/20260218152330.GI26902@suse.cz/
Assisted-by: Codex:GPT-5.6
Signed-off-by: Qingfang Deng <qingfang.deng@linux.dev>
Reviewed-by: David Sterba <dsterba@suse.com>
Acked-by: David Sterba <dsterba@suse.com>
Acked-by: Jiri Kosina <jkosina@suse.com>
Link: https://patch.msgid.link/20260803091938.259944-1-qingfang.deng@linux.dev
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The vt_setactivate() function accepts any mode value without validation,
while VT_SETMODE correctly rejects invalid values (only VT_AUTO and
VT_PROCESS are valid).
This allows users to set invalid mode values (e.g., 0xFF) which bypasses
VT_PROCESS signal handling and causes undefined VT switching behavior.
Fix this by adding the same validation as VT_SETMODE.
Signed-off-by: Wang Zihan <jiyu03@qq.com>
Link: https://patch.msgid.link/tencent_6A7DAE2E1288663D23AACBE2950D6E535007@qq.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The GENI main sequencer handles console TX while the secondary sequencer
handles FIFO RX. Before nbcon, the legacy console writer disabled both
interrupt domains while it performed a long polled M-side transfer. This
left the small S-side FIFO unserviced, allowing console input to overrun
and be lost.
The nbcon conversion replaces IRQ masking with the UART port lock, but a
threaded console write still prevents the RX handler from draining the
FIFO. Keep S-side RX enabled independently of M-side TX and drain it
while refilling each bounded console command. This preserves interactive
input during console output.
Atomic output masks only M-side TX state, leaving FIFO RX handling
independent. The threaded writer can also detect a SysRq character while
it drains RX, so defer delivery until device_unlock() drops the UART port
lock, as the existing IRQ path does with uart_unlock_and_check_sysrq().
Assisted-by: OpenCode:GPT-5.5
Signed-off-by: Bjorn Andersson <bjorn.andersson@oss.qualcomm.com>
Link: https://patch.msgid.link/20260729-qcom-geni-nbcon-v1-2-3053b96465ed@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The legacy GENI console writer serializes every message around a
synchronous polled M-side transfer. It blocks printk callers for UART
wire time and cannot provide atomic output while normal console output is
active.
Convert the console to nbcon threaded and atomic writers. Use the UART
port lock as the device lock and bound threaded M-side commands so
urgent diagnostics can take over atomic output. The threaded writer is
batching the output in 32-source-byte commands, a value chosen to
balance the command setup overhead with atomic-handoff latency.
Atomic output can cancel an active normal TX command. Use irq_work to
resume queued TTY output afterward, honor flow control, and prevent the
deferred restart from accessing the port during shutdown or removal.
Assisted-by: OpenCode:GPT-5.5
Signed-off-by: Bjorn Andersson <bjorn.andersson@oss.qualcomm.com>
Link: https://patch.msgid.link/20260729-qcom-geni-nbcon-v1-1-3053b96465ed@oss.qualcomm.com
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, acquire a runtime PM
reference with pm_runtime_resume_and_get() before uart_add_one_port()
and release it with pm_runtime_put() 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/20260720-remove_uart_change_state-v2-1-30153ce4333b@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This driver doesn't really need to split the registration of the GPIO
chip into stages, as platform_device_info already provides fields for
the firmware node, parent device and the software node. Use
platform_device_register_full() and simplify the code. This also
addresses the problem with incorrect reference count of the assigned
firmware node.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Link: https://patch.msgid.link/20260728-exar-pdev-reg-full-v1-1-7a96e77309e1@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Coccinelle warns about missing clk_put on the error path after clk_get,
but the error path returns with an ERR_PTR where clk_put must not be
called. Restructure into a single if block so the logic is clear to
silence false positive coccinelle warning.
Commit 580d952e44 ("tty: serial: bcm63xx: fix missing clk_put() in
bcm63xx_uart") previously tried to fix this same warning by adding a
clk_put, which was reverted because it was wrong.
Prevent anyone from making the same mistake again.
Signed-off-by: Pei Xiao <xiaopei01@kylinos.cn>
Link: https://patch.msgid.link/604886147edb67c3ed85b192eb3f7a4a6dd0f0ac.1784788388.git.xiaopei01@kylinos.cn
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 is no
longer necessary since commit 16ae2a877b ("serial: Fix crash if the
minimum rate of the device is > 9600 baud") so remove it.
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260720193411.3517484-1-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 is no
longer necessary since commit 16ae2a877b ("serial: Fix crash if the
minimum rate of the device is > 9600 baud") so remove it.
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260720195147.3630241-1-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 3d9e6f556e.
The 8250 driver no longer depends on @oops_in_progress and
will no longer violate the port->lock locking constraints.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://patch.msgid.link/20260729120439.281252-3-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Implement the necessary callbacks to switch the 8250 console driver
to perform as an nbcon console.
Add implementations for the nbcon console callbacks:
->write_atomic()
->write_thread()
->device_lock()
->device_unlock()
and add CON_NBCON to the initial @flags.
All hardware access in the callbacks is within unsafe sections.
The ->write_atomic() and ->write_thread() callbacks allow safe
handover/takeover per byte and add a preceding newline if they
take over from another context mid-line.
For the ->write_atomic() callback, a new irq_work is used to defer
modem control since it may be called from a context that does not
allow waking up tasks. During suspend/resume the irq_work is not
used as this has been shown to cause suspend problems for some
hardware. Upon resume, any pending modem control is performed.
Note: A new __serial8250_clear_IER() is introduced for direct
clearing of UART_IER during console writing (which will not be
holding the port lock for atomic printing or KDB/KGDB). This
allows restoring a lockdep check to serial8250_clear_IER() in
a follow-up commit.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://patch.msgid.link/20260729120439.281252-2-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The inclusion of <linux/kconfig.h> in commit 7ab80d1e72 ("serial: 8250:
fix compile error with hub6_match_port() when compiled as a module") is
unneeded as it's guaranteed by the build starting from commit 2a11c8ea20
("kconfig: Introduce IS_ENABLED(), IS_BUILTIN() and IS_MODULE()").
Remove it here.
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20260721144847.3728422-1-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The inclusion of <linux/kconfig.h> in commit f18643843b ("serial:
max310x: fix compile errors if CONFIG_SPI_MASTER is disabled") is
unneeded as it's guaranteed by the build starting from the commit
2a11c8ea20 ("kconfig: Introduce IS_ENABLED(), IS_BUILTIN() and
IS_MODULE()"). Remove it here.
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20260721144420.3727708-1-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When transmit flushing a qcom-geni UART during an ongoing TX DMA, the
UART gets stuck infinitely repeating corrupted TX DMA frames.
The DMA-mode uart_ops does not provide a flush_buffer callback, so an
in-flight transfer can complete after serial core has reset the transmit
kfifo, underflowing its length and resubmitting page-sized transfers
indefinitely. Add one that stops the transfer and clears tx_remaining
and tx_queued.
The stop path was also broken: it unmapped the buffer while the serial
engine could still read it, and never reset the TX DMA state machine.
Cancel the main sequencer command first, then reset the state machine
and wait for it before unmapping. Drop the early return so a pending
mapping is also cleaned up when the main command is inactive.
The bug can be triggered from userspace with a large write immediately
followed by TCOFLUSH. A following tcdrain will hang forever. The bug was
reproduced and this fix was validated on Arduino Uno Q (QRB2210)
using /dev/ttyHS1.
Assisted-by: Claude:claude-5-opus Codex:gpt-5
Signed-off-by: Jan Sebastian Götte <linux@jaseg.de>
Fixes: 2aaa43c707 ("tty: serial: qcom-geni-serial: add support for serial engine DMA")
Cc: stable <stable@kernel.org>
Reviewed-by: Praveen Talari <praveen.talari@oss.qualcomm.com>
Link: https://patch.msgid.link/20260729174105.21838-2-git@jaseg.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial8250_release_dma() terminates RX DMA and releases the channel, but
leaves rx_running set. If the port is closed while an RX transfer is
active, the stale state remains while rxchan is NULL until the channel is
requested again on the next open.
The DesignWare BUSY workaround added by commit a7b9ce39fb
("serial: 8250_dw: Ensure BUSY is deasserted") calls
serial8250_rx_dma_flush() from the LCR write path during startup. This
happens before serial8250_request_dma() obtains a new RX channel. On
reopen, the stale rx_running state therefore makes the flush path pass a
NULL channel to dmaengine_pause(), causing a kernel Oops.
Clear rx_running after terminating RX DMA, matching the TX cleanup. Also
make the flush helper return if the DMA object or RX channel is not
available so startup and teardown paths cannot pass a NULL channel to the
DMAengine API.
Fixes: 0fcb7901f9 ("tty: serial: 8250_dma: keep own book keeping about RX transfers")
Cc: stable <stable@kernel.org>
Signed-off-by: Cunhao Lu <1579567540@qq.com>
Link: https://patch.msgid.link/tencent_9EE2945F4C933B4D810C73C2D7485E000F06@qq.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sc16is7xx_handle_tx() currently requests the THRI enable only after it has
filled the TX FIFO. The request is asynchronous because the IER update is
performed later by reg_work.
The SC16IS7xx generates a THRI interrupt when the TX FIFO crosses its
trigger level. If the FIFO drains past that level before reg_work enables
THRI, the chip does not generate a new interrupt. Characters remain queued
indefinitely even though the hardware FIFO is empty.
This was observed on an SC16IS752 while both UART channels were active.
During the stall the software TX buffer remained non-empty while TXLVL
reported 64 bytes free, LSR reported THR and transmitter empty, IER had
THRI enabled, and IIR reported no interrupt pending.
Enable THRI synchronously before filling the FIFO so the threshold crossing
cannot be missed.
Fixes: cc4c1d05eb ("sc16is7xx: Properly resume TX after stop")
Cc: stable <stable@kernel.org>
Signed-off-by: Luca Fresi <luca.fresi@bithiatec.com>
Link: https://patch.msgid.link/20260721222404.204746-1-luca.fresi@bithiatec.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit d338ab1d90.
uart_console() only indicates that the port is selected as the console.
It does not mean that the console has already been registered or has
printed the buffered messages.
On platforms where an initial 8250 port is replaced when the real UART
device is registered, clearing CON_PRINTBUFFER causes the console to
start at the end of the printk ring buffer. Without earlycon, all
messages logged before UART registration are therefore lost.
Fixes: d338ab1d90 ("serial: 8250: Clear CON_PRINTBUFFER on port re-registration")
Reported-by: Mark Brown <broonie@kernel.org>
Reported-by: Anirudh Srinivasan <asrinivasan@oss.tenstorrent.com>
Link: https://lore.kernel.org/all/20260522101042.21976-1-fushuai.wang@linux.dev/
Signed-off-by: Fushuai Wang <wangfushuai@baidu.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Link: https://patch.msgid.link/20260724093151.53216-1-fushuai.wang@linux.dev
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CONFIG_PRINT_QUOTA_WARNING was marked as BROKEN in 2023 by 36d532d713
("quota: mark PRINT_QUOTA_WARNING as BROKEN").
The code is apparently unused and uninteresting, so remove it all, incl.
the abuse of TTY.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jan Kara <jack@suse.com>
Cc: Yangtao Li <frank.li@vivo.com>
Link: https://patch.msgid.link/20260722060155.1111519-1-jirislaby@kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Implement the basic serial device bus abstractions required to write a
serial device bus device driver with or without the need for initial device
data. This includes the following data structures:
The `serdev::Driver` trait represents the interface to the driver.
The `serdev::Device` abstraction represents a `struct serdev_device`.
In order to provide the Serdev specific parts to a generic
`driver::Registration` the `driver::RegistrationOps` trait is
implemented by `serdev::Adapter`.
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Markus Probst <markus.probst@posteo.de>
Link: https://patch.msgid.link/20260718-rust_serdev-v16-1-5809384d2e1b@posteo.de
Signed-off-by: Danilo Krummrich <dakr@kernel.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.
Fixes: dfeae619d7 ("serial: sc16is7xx")
Cc: stable <stable@kernel.org>
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Acked-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Link: https://patch.msgid.link/20260716210813.2582826-1-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit b1b4efea05 ("serial: 8250_mid: Disable DMA for selected
platforms") replaced the dnv_board setup and exit callbacks with
PTR_IF(false, ...), which evaluates to NULL. However, the three call
sites in mid8250_probe() and mid8250_remove() unconditionally
dereference these function pointers without NULL checks, causing a NULL
pointer dereference (kernel oops) on any Denverton (DNV), Ice Lake Xeon
D (ICX-D/CDF), or Snowridge (SNR) platform.
Fix this by adding the missing NULL checks before calling the setup and
exit callbacks.
Fixes: b1b4efea05 ("serial: 8250_mid: Disable DMA for selected platforms")
Cc: stable <stable@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jiangshan Yi <yijiangshan@kylinos.cn>
Link: https://patch.msgid.link/20260715073546.1875083-1-yijiangshan@kylinos.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
hvc_dcc drives the JTAG DCC via the ARMv6/v7 CP14 debug registers
(mrc/mcr p14, 0, rX, c0, c1/c5, 0 in asm/dcc.h). That encoding is
undefined on older ARM cores, and also on ARMv7-M, but HVC_DCC only
depends on ARM, so it can be enabled on e.g. ARM926 (ARCH_MULTI_V5),
where hvc_dcc_console_init() runs __dcc_putchar() at boot and takes an
undefined-instruction trap before the console is up:
Internal error: Oops - undefined instruction: 0 [#1] ARM
PC is at hvc_dcc_check+0x50/0x8c
hvc_dcc_check from hvc_dcc_console_init+0x18/0x48
hvc_dcc_console_init from console_init+0x58/0x170
Kernel panic - not syncing: Fatal exception
Restrict HVC_DCC to the CPUs where that encoding is valid: the
CPU_V6 || CPU_V6K || CPU_V7 set that arch/arm/include/debug/icedcc.S
guards it with, plus ARM64.
Fixes: 16c63f8ea4 ("drivers: char: hvc: add arm JTAG DCC console support")
Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Link: https://patch.msgid.link/20260717071616.91423-1-kmehltretter@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
