Re: [PATCH] ACPI: button: Report wakeup key only for power button wakeups

On Thu, Aug 6, 2026 at 2:28 PM Baorui Liu <[email protected]> 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 <[email protected]>
> ---
>  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
>