kernel/drivers/base/power/wakeirq.c, branch linux-rolling-stable

PM: sleep: wakeirq: harden dev_pm_clear_wake_irq() against races

2026-02-26T22:59:01Z

[ Upstream commit 5c9ecd8e6437cd55a38ea4f1e1d19cee8e226cb8 ] dev_pm_clear_wake_irq() currently uses a dangerous pattern where dev->power.wakeirq is read and checked for NULL outside the lock. If two callers invoke this function concurrently, both might see a valid pointer and proceed. This could result in a double-free when the second caller acquires the lock and tries to release the same object. Address this by removing the lockless check of dev->power.wakeirq. Instead, acquire dev->power.lock immediately to ensure the check and the subsequent operations are atomic. If dev->power.wakeirq is NULL under the lock, simply unlock and return. This guarantees that concurrent calls cannot race to free the same object. Based on a quick scan of current users, I did not find an actual bug as drivers seem to rely on their own synchronization. However, since asynchronous usage patterns exist (e.g., in drivers/net/wireless/ti/wlcore), I believe a race is theoretically possible if the API is used less carefully in the future. This change hardens the API to be robust against such cases. Fixes: 4990d4fe327b ("PM / Wakeirq: Add automated device wake IRQ handling") Signed-off-by: Gui-Dong Han Link: https://patch.msgid.link/20260203031943.1924-1-hanguidong02@gmail.com Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

PM: sleep: wakeirq: Introduce device-managed variant of dev_pm_set_wake_irq()

2025-01-17T19:27:46Z

Add device-managed variant of dev_pm_set_wake_irq which automatically clear the wake irq on device destruction to simplify error handling and resource management in drivers. Signed-off-by: Peng Fan Link: https://patch.msgid.link/20250103-wake_irq-v2-1-e3aeff5e9966@nxp.com Signed-off-by: Rafael J. Wysocki

PM: sleep: wakeirq: fix wake irq warning in system suspend

2024-03-05T11:39:05Z

When driver uses pm_runtime_force_suspend() as the system suspend callback function and registers the wake irq with reverse enable ordering, the wake irq will be re-enabled when entering system suspend, triggering an 'Unbalanced enable for IRQ xxx' warning. In this scenario, the call sequence during system suspend is as follows: suspend_devices_and_enter() -> dpm_suspend_start() -> dpm_run_callback() -> pm_runtime_force_suspend() -> dev_pm_enable_wake_irq_check() -> dev_pm_enable_wake_irq_complete() -> suspend_enter() -> dpm_suspend_noirq() -> device_wakeup_arm_wake_irqs() -> dev_pm_arm_wake_irq() To fix this issue, complete the setting of WAKE_IRQ_DEDICATED_ENABLED flag in dev_pm_enable_wake_irq_complete() to avoid redundant irq enablement. Fixes: 8527beb12087 ("PM: sleep: wakeirq: fix wake irq arming") Reviewed-by: Dhruva Gole Signed-off-by: Qingliang Li Reviewed-by: Johan Hovold Cc: 5.16+ # 5.16+ Signed-off-by: Rafael J. Wysocki

PM: sleep: wakeirq: drop unused enable helpers

2023-07-24T07:51:51Z

Drop the wake-irq enable and disable helpers which have not been used since commit bed570307ed7 ("PM / wakeirq: Fix dedicated wakeirq for drivers not using autosuspend"). Note that these functions are essentially just leftovers from the first iteration of the wake-irq implementation where device drivers were supposed to call these functions themselves instead of PM core (as is also indicated by the bogus kernel doc comments). Signed-off-by: Johan Hovold Reviewed-by: Tony Lindgren Signed-off-by: Rafael J. Wysocki

PM: sleep: wakeirq: fix wake irq arming

2023-07-24T07:51:51Z

The decision whether to enable a wake irq during suspend can not be done based on the runtime PM state directly as a driver may use wake irqs without implementing runtime PM. Such drivers specifically leave the state set to the default 'suspended' and the wake irq is thus never enabled at suspend. Add a new wake irq flag to track whether a dedicated wake irq has been enabled at runtime suspend and therefore must not be enabled at system suspend. Note that pm_runtime_enabled() can not be used as runtime PM is always disabled during late suspend. Fixes: 69728051f5bf ("PM / wakeirq: Fix unbalanced IRQ enable for wakeirq") Cc: 4.16+ # 4.16+ Signed-off-by: Johan Hovold Reviewed-by: Tony Lindgren Tested-by: Tony Lindgren Signed-off-by: Rafael J. Wysocki

PM: sleep: wakeup: Fix typos in comments

2022-03-01T15:17:32Z

Remove the second 'the'. Replace the second 'of' with 'the'. Replace 'couter' with 'counter'. Signed-off-by: Tom Rix Acked-by: Randy Dunlap Acked-by: Pavel Machek Signed-off-by: Rafael J. Wysocki

PM / wakeirq: support enabling wake-up irq after runtime_suspend called

2021-10-27T18:49:32Z

When the dedicated wake IRQ is level trigger, and it uses the device's low-power status as the wakeup source, that means if the device is not in low-power state, the wake IRQ will be triggered if enabled; For this case, need enable the wake IRQ after running the device's ->runtime_suspend() which make it enter low-power state. e.g. Assume the wake IRQ is a low level trigger type, and the wakeup signal comes from the low-power status of the device. The wakeup signal is low level at running time (0), and becomes high level when the device enters low-power state (runtime_suspend (1) is called), a wakeup event at (2) make the device exit low-power state, then the wakeup signal also becomes low level. ------------------ | ^ ^| ---------------- | | -------------- |<---(0)--->|<--(1)--| (3) (2) (4) if enable the wake IRQ before running runtime_suspend during (0), a wake IRQ will arise, it causes resume immediately; it works if enable wake IRQ ( e.g. at (3) or (4)) after running ->runtime_suspend(). This patch introduces a new status WAKE_IRQ_DEDICATED_REVERSE to optionally support enabling wake IRQ after running ->runtime_suspend(). Suggested-by: Rafael J. Wysocki Signed-off-by: Chunfeng Yun Signed-off-by: Rafael J. Wysocki

PM: sleep: wakeirq: drop useless parameter from dev_pm_attach_wake_irq()

2021-09-07T19:10:09Z

This function has the 'irq' parameter which isn't ever used, so drop it. Signed-off-by: Sergey Shtylyov [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki

PM: wakeirq: Set IRQF_NO_AUTOEN when requesting the IRQ

2021-05-24T14:06:17Z

request_irq() after setting IRQ_NOAUTOEN as below irq_set_status_flags(irq, IRQ_NOAUTOEN); request_irq(dev, irq...); can be replaced by request_irq() with IRQF_NO_AUTOEN flag. This change is just to simplify the code, no actual functional changes. Signed-off-by: Tian Tao Reviewed-by: Tony Lindgren [ rjw: Subject ] Signed-off-by: Rafael J. Wysocki

PM / wakeirq: remove unnecessary parentheses

2019-11-13T10:31:08Z

Remove unnecessary parentheses found by code review. Signed-off-by: Xiaofei Tan Signed-off-by: Rafael J. Wysocki