The for_each_endpoint_of_node() macro requires calling of_node_put() on the
endpoint node when breaking out of the loop early.
Add of_node_put(endpoint) before the early return to release the reference.
Fixes: cf3287fb2c ("PCI/pwrctrl: Ensure that remote endpoint node parent has supply requirement")
Signed-off-by: Felix Gu <ustc.gu@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Link: https://patch.msgid.link/20260323-pwctrl-v1-1-f5c03a2df7fb@gmail.com
If OF graph is used in the PCI device node, the pwrctrl core creates a
pwrctrl device even if the remote endpoint doesn't have power supply
requirements. Since the device doesn't have any power supply requirements,
there was no pwrctrl driver to probe, leading to PCI controller driver
probe deferral as it waits for all pwrctrl drivers to probe before starting
bus scan.
This issue happens with Qcom ath12k devices with WSI interface attached to
the Qcom IPQ platforms.
Fix this issue by checking for the existence of at least one power supply
property in the remote endpoint parent node. To consolidate all the checks,
create a new helper pci_pwrctrl_is_required() and move all the checks
there.
Fixes: 9db826206f ("PCI/pwrctrl: Create pwrctrl device if graph port is found")
Reported-by: Raj Kumar Bhagat <raj.bhagat@oss.qualcomm.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Raj Kumar Bhagat <raj.bhagat@oss.qualcomm.com>
Reviewed-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Link: https://patch.msgid.link/20260223-pwrctrl-fixes-7-0-v2-1-97566dfb1809@oss.qualcomm.com
The devicetree node of the PCIe Root Port/Slot could have the graph port to
link the PCIe M.2 connector node. Since the M.2 connectors are modeled as
Power Sequencing devices, they need to be controlled by the pwrctrl driver
like the Root Port/Slot supplies.
Hence, create the pwrctrl device if the graph port is found in the node.
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Link: https://patch.msgid.link/20260128-pci-m2-v7-2-9b3a5fe3d244@oss.qualcomm.com
Adopt pwrctrl APIs to create, power on/off, and destroy pwrctrl devices.
In qcom_pcie_host_init(), call pci_pwrctrl_create_devices() to create
devices, then pci_pwrctrl_power_on_devices() to power them on, both after
controller resource initialization. Once successful, deassert PERST# for
all devices.
In qcom_pcie_host_deinit(), call pci_pwrctrl_power_off_devices() after
asserting PERST#. Note that pci_pwrctrl_destroy_devices() is not called
here, as deinit is only invoked during system suspend where device
destruction is unnecessary. If the driver becomes removable in future,
pci_pwrctrl_destroy_devices() should be called in the remove() handler.
Remove the old pwrctrl framework code from the PCI core (including
devlinks) as the new APIs are now the sole consumer of pwrctrl
functionality. And also do not power on the pwrctrl drivers during probe()
as this is now handled by the APIs.
Co-developed-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Link: https://patch.msgid.link/20260115-pci-pwrctrl-rework-v5-12-9d26da3ce903@oss.qualcomm.com
To fix bridge resource allocation issues when powering PCI bridges with the
pwrctrl driver, introduce APIs to explicitly power on and off all related
devices simultaneously.
Previously, the individual pwrctrl drivers powered on/off the PCI devices
autonomously, without any control from the controller drivers. But to
enforce ordering with respect to powering on the devices, these APIs will
power on/off all the devices at the same time.
The pci_pwrctrl_power_on_devices() API recursively scans the PCI child
nodes, makes sure that pwrctrl drivers are bound to devices, and calls
their power_on() callbacks. If any pwrctrl driver is not bound, it will
return -EPROBE_DEFER.
Similarly, pci_pwrctrl_power_off_devices() API powers off devices
recursively via their power_off() callbacks.
These APIs are expected to be called during the controller probe and
suspend/resume time to power on/off the devices. But before calling these
APIs, the pwrctrl devices should be created using the
pci_pwrctrl_{create/destroy}_devices() APIs.
Co-developed-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Link: https://patch.msgid.link/20260115-pci-pwrctrl-rework-v5-11-9d26da3ce903@oss.qualcomm.com
Previously, the PCI core created pwrctrl devices during pci_scan_device()
on its own and then skipped enumeration of those devices, hoping the
pwrctrl driver would power them on and trigger a bus rescan.
This approach works for endpoint devices directly connected to Root Ports,
but it fails for PCIe switches acting as bus extenders. When the switch
requires pwrctrl support and the pwrctrl driver is not available during
the pwrctrl device creation, its enumeration will be skipped during the
initial PCI bus scan.
This premature scan leads the PCI core to allocate resources (bridge
windows, bus numbers) for the upstream bridge based on available downstream
buses at scan time. For non-hotplug capable bridges, PCI core typically
allocates resources based on the number of buses available during the
initial bus scan, which happens to be just one if the switch is not powered
on and enumerated at that time. When the switch gets enumerated later on,
it will fail due to the lack of upstream resources.
As a result, a PCIe switch powered on by the pwrctrl driver cannot be
reliably enumerated currently. Either the switch has to be enabled in the
bootloader or the switch pwrctrl driver has to be loaded during the pwrctrl
device creation time to work around these issues.
Introduce new APIs to explicitly create and destroy pwrctrl devices from
controller drivers by recursively scanning the PCI child nodes of the
controller. These APIs allow creating pwrctrl devices based on the original
criteria and are intended to be called during controller probe and removal.
These APIs, together with the upcoming APIs for power on/off will allow the
controller drivers to power on all the devices before starting the initial
bus scan, thereby solving the resource allocation issue.
Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
[mani: splitted the patch, cleaned up the code, and rewrote description]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Link: https://patch.msgid.link/20260115-pci-pwrctrl-rework-v5-10-9d26da3ce903@oss.qualcomm.com
It's possible to trigger use-after-free here by:
(a) forcing rescan_work_func() to take a long time and
(b) utilizing a pwrctrl driver that may be unloaded for some reason
Cancel outstanding work to ensure it is finished before we allow our data
structures to be cleaned up.
[bhelgaas: tidy commit log]
Fixes: 8f62819aaa ("PCI/pwrctl: Rescan bus on a separate thread")
Signed-off-by: Brian Norris <briannorris@google.com>
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Cc: Konrad Dybcio <konradybcio@kernel.org>
Link: https://patch.msgid.link/20250409115313.1.Ia319526ed4ef06bec3180378c9a008340cec9658@changeid
Current way of creating pwrctrl devices requires iterating through the
child devicetree nodes of the PCI bridge in pci_pwrctrl_create_devices().
Even though it works, it creates confusion as there is no symmetry between
this and pci_pwrctrl_unregister() function that removes the pwrctrl
devices.
So to make these two functions symmetric, move the creation of pwrctrl
devices to pci_scan_device(). During the scan of each device in a slot,
the devicetree node (if exists) for the PCI device will be checked. If it
has the supplies populated, then the pwrctrl device will be created.
Since the PCI device scan happens so early, there would be no "struct
pci_dev" available for the device. So the host bridge is used as the
parent of all pwrctrl devices.
One nice side effect of this move is that, it is now possible to have
pwrctrl devices for PCI bridges as well (to control the supplies of PCI
slots).
Suggested-by: Lukas Wunner <lukas@wunner.de>
Tested-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20250116-pci-pwrctrl-slot-v3-1-827473c8fbf4@linaro.org
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Rename pwrctrl functions and structures from "pwrctl" to "pwrctrl" to match
the similar file renames.
Link: https://lore.kernel.org/r/20241115214428.2061153-3-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Acked-by: Krzysztof Wilczyński <kw@linux.com>
To slightly reduce confusion between "pwrctl" (the power controller and
power sequencing framework) and "bwctrl" (the bandwidth controller),
rename "pwrctl" to "pwrctrl" so they use the same "ctrl" suffix.
Rename drivers/pci/pwrctl/ to drivers/pci/pwrctrl/, including the related
MAINTAINERS, include file (include/linux/pci-pwrctl.h), Makefile, and
Kconfig changes.
This is the minimal rename of files only. A subsequent commit will rename
functions and data structures.
Link: https://lore.kernel.org/r/20241115214428.2061153-2-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Acked-by: Krzysztof Wilczyński <kw@linux.com>
