Re: [PATCH] ACPI: button: Report wakeup key only for power button wakeups
From: Rafael J. Wysocki (Intel)
Date: Fri Aug 07 2026 - 10:15:01 EST
On Thu, Aug 6, 2026 at 2:28 PM Baorui Liu <baorliu@xxxxxxx> wrote:
>
> Commit 16f70feaabe9 ("ACPI: button: trigger wakeup key events")
> makes the ACPI power button driver report KEY_WAKEUP from its resume
> callback. However, that callback is run whenever the ACPI button device
> is resumed, regardless of the actual system wakeup source.
>
> As a result, userspace may receive a KEY_WAKEUP event after resumes
> caused by unrelated wakeup sources.
So why is this a problem in practice?
> Avoid reporting the input event from acpi_button_resume(). Instead,
> report it only when the ACPI fixed power button status indicates that
> the power button was the wakeup source.
But power buttons need not be fixed event devices and there are also
sleep buttons that can generate KEY_WAKEUP, and what about lids?
> Fixes: 16f70feaabe9 ("ACPI: button: trigger wakeup key events")
> Signed-off-by: Baorui Liu <baorliu@xxxxxxx>
> ---
> drivers/acpi/button.c | 23 +++++++++++++++--------
> drivers/acpi/sleep.c | 21 +++++++++++++++++++++
> drivers/acpi/sleep.h | 1 +
> drivers/acpi/x86/s2idle.c | 4 +++-
> include/acpi/button.h | 5 +++++
> 5 files changed, 45 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c
> index 3836ee75dd66..700510f6e5d0 100644
> --- a/drivers/acpi/button.c
> +++ b/drivers/acpi/button.c
> @@ -480,6 +480,21 @@ static void acpi_button_notify(acpi_handle handle, u32 event, void *data)
> event, ++button->pushed);
> }
>
> +void acpi_power_button_wakeup(struct acpi_device *device)
> +{
> + struct acpi_button *button = acpi_driver_data(device);
> + struct input_dev *input;
> +
> + if (button->type == ACPI_BUTTON_TYPE_POWER) {
> + input = button->input;
> + input_report_key(input, KEY_WAKEUP, 1);
> + input_sync(input);
> + input_report_key(input, KEY_WAKEUP, 0);
> + input_sync(input);
> + }
> +}
> +EXPORT_SYMBOL(acpi_power_button_wakeup);
> +
> static void acpi_button_notify_run(void *data)
> {
> acpi_button_notify(NULL, ACPI_BUTTON_NOTIFY_STATUS, data);
> @@ -503,7 +518,6 @@ static int acpi_button_suspend(struct device *dev)
> static int acpi_button_resume(struct device *dev)
> {
> struct acpi_button *button = dev_get_drvdata(dev);
> - struct input_dev *input;
>
> button->suspended = false;
> if (button->type == ACPI_BUTTON_TYPE_LID) {
> @@ -512,13 +526,6 @@ static int acpi_button_resume(struct device *dev)
> acpi_lid_initialize_state(button);
> }
>
> - if (button->type == ACPI_BUTTON_TYPE_POWER) {
> - input = button->input;
> - input_report_key(input, KEY_WAKEUP, 1);
> - input_sync(input);
> - input_report_key(input, KEY_WAKEUP, 0);
> - input_sync(input);
> - }
> return 0;
> }
> #endif
> diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
> index 132a9df98471..26bbecd0c166 100644
> --- a/drivers/acpi/sleep.c
> +++ b/drivers/acpi/sleep.c
> @@ -22,6 +22,7 @@
> #include <linux/syscore_ops.h>
> #include <asm/io.h>
> #include <trace/events/power.h>
> +#include <acpi/button.h>
>
> #include "internal.h"
> #include "sleep.h"
> @@ -518,6 +519,7 @@ static void acpi_pm_finish(void)
> NULL, -1);
> if (pwr_btn_adev) {
> pm_wakeup_event(&pwr_btn_adev->dev, 0);
> + acpi_power_button_wakeup(pwr_btn_adev);
> acpi_dev_put(pwr_btn_adev);
> }
> }
> @@ -818,6 +820,24 @@ bool acpi_s2idle_wake(void)
> return false;
> }
>
> +void acpi_s2idle_restore_check_powerkey(void)
> +{
> + struct acpi_device *pwr_btn_adev;
> + acpi_event_status pwr_btn_status = ACPI_EVENT_FLAG_DISABLED;
> +
> + acpi_get_event_status(ACPI_EVENT_POWER_BUTTON, &pwr_btn_status);
> +
> + if (pwr_btn_status & ACPI_EVENT_FLAG_STATUS_SET) {
> + pwr_btn_adev = acpi_dev_get_first_match_dev(ACPI_BUTTON_HID_POWERF,
> + NULL, -1);
> + if (pwr_btn_adev) {
> + pm_wakeup_event(&pwr_btn_adev->dev, 0);
> + acpi_power_button_wakeup(pwr_btn_adev);
> + acpi_dev_put(pwr_btn_adev);
> + }
> + }
> +}
> +
> void acpi_s2idle_restore(void)
> {
> /*
> @@ -849,6 +869,7 @@ static const struct platform_s2idle_ops acpi_s2idle_ops = {
> .begin = acpi_s2idle_begin,
> .prepare = acpi_s2idle_prepare,
> .wake = acpi_s2idle_wake,
> + .restore_early = acpi_s2idle_restore_check_powerkey,
> .restore = acpi_s2idle_restore,
> .end = acpi_s2idle_end,
> };
> diff --git a/drivers/acpi/sleep.h b/drivers/acpi/sleep.h
> index 9c3cb109c5d2..50382c90446c 100644
> --- a/drivers/acpi/sleep.h
> +++ b/drivers/acpi/sleep.h
> @@ -18,6 +18,7 @@ static inline acpi_status acpi_set_waking_vector(u32 wakeup_address)
> extern int acpi_s2idle_begin(void);
> extern int acpi_s2idle_prepare(void);
> extern bool acpi_s2idle_wake(void);
> +extern void acpi_s2idle_restore_check_powerkey(void);
> extern void acpi_s2idle_restore(void);
> extern void acpi_s2idle_end(void);
>
> diff --git a/drivers/acpi/x86/s2idle.c b/drivers/acpi/x86/s2idle.c
> index b6b1dd76a06b..ce6663c1ef70 100644
> --- a/drivers/acpi/x86/s2idle.c
> +++ b/drivers/acpi/x86/s2idle.c
> @@ -598,8 +598,10 @@ static void acpi_s2idle_restore_early_lps0(void)
> {
> struct acpi_s2idle_dev_ops *handler;
>
> - if (!lps0_device_handle || sleep_no_lps0)
> + if (!lps0_device_handle || sleep_no_lps0) {
> + acpi_s2idle_restore_check_powerkey();
> return;
> + }
>
> list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node)
> if (handler->restore)
> diff --git a/include/acpi/button.h b/include/acpi/button.h
> index af2fce5d2ee3..3cbf3272371e 100644
> --- a/include/acpi/button.h
> +++ b/include/acpi/button.h
> @@ -8,11 +8,16 @@
>
> #if IS_ENABLED(CONFIG_ACPI_BUTTON)
> extern int acpi_lid_open(void);
> +extern void acpi_power_button_wakeup(struct acpi_device *device);
> #else
> static inline int acpi_lid_open(void)
> {
> return 1;
> }
> +
> +static inline void acpi_power_button_wakeup(struct acpi_device *device)
> +{
> +}
> #endif /* IS_ENABLED(CONFIG_ACPI_BUTTON) */
>
> #endif /* ACPI_BUTTON_H */
>
> base-commit: 4d823c9d06aaa91476b58e56e4d44c4112da2811
> --
> 2.34.1
>