Re: [PATCH] ACPI: button: Support separate press and release events

[Rafael J. Wysocki (Intel)]

On Tue, Oct 13, 2026 at 8:39 AM <liujinlong176@xxxxxxx> wrote:
>
> From: liujinlong <liujinlong@xxxxxxxxxx>
>
> The ACPI button driver only recognizes notify value 0x80 and
> always synthesizes a press followed by an immediate release.
> This makes it impossible for userspace to determine the actual
> duration of a power button press.
>
> Add two new notify values, 0x81 and 0x82, that firmware can use
> to report the press and the release separately.  The 0x80 path
> is unchanged for compatibility with existing firmware.

You'd need to update the ACPI specification first as that's where the
notification values are defined.

> Move the notify value definitions to include/acpi/button.h so
> they can be shared between the driver and other users.
>
> Signed-off-by: liujinlong <liujinlong@xxxxxxxxxx>
> ---
>  drivers/acpi/button.c | 24 ++++++++++++++++++------
>  include/acpi/button.h |  4 ++++
>  2 files changed, 22 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c
> index cdbb1023a8ee..b72ed9fc429d 100644
> --- a/drivers/acpi/button.c
> +++ b/drivers/acpi/button.c
> @@ -26,7 +26,6 @@
>  #define ACPI_BUTTON_FILE_STATE         "state"
>  #define ACPI_BUTTON_TYPE_UNKNOWN       0x00
>  #define ACPI_BUTTON_NOTIFY_WAKE                0x02
> -#define ACPI_BUTTON_NOTIFY_STATUS      0x80
>
>  #define ACPI_BUTTON_CLASS_POWER                "button/power"
>  #define ACPI_BUTTON_DEVICE_NAME_POWER  "Power Button"
> @@ -465,7 +464,8 @@ static void acpi_button_notify(acpi_handle handle, u32 event, void *data)
>
>         switch (event) {
>         case ACPI_BUTTON_NOTIFY_STATUS:
> -               break;
> +       case ACPI_BUTTON_NOTIFY_PRESS:
> +       case ACPI_BUTTON_NOTIFY_RELEASE:
>         case ACPI_BUTTON_NOTIFY_WAKE:
>                 break;
>         default:
> @@ -482,10 +482,22 @@ static void acpi_button_notify(acpi_handle handle, u32 event, void *data)
>         input = button->input;
>         keycode = test_bit(KEY_SLEEP, input->keybit) ? KEY_SLEEP : KEY_POWER;
>
> -       input_report_key(input, keycode, 1);
> -       input_sync(input);
> -       input_report_key(input, keycode, 0);
> -       input_sync(input);
> +       switch (event) {
> +       case ACPI_BUTTON_NOTIFY_STATUS:
> +               input_report_key(input, keycode, 1);
> +               input_sync(input);
> +               input_report_key(input, keycode, 0);
> +               input_sync(input);
> +               break;
> +       case ACPI_BUTTON_NOTIFY_PRESS:
> +               input_report_key(input, keycode, 1);
> +               input_sync(input);
> +               break;
> +       case ACPI_BUTTON_NOTIFY_RELEASE:
> +               input_report_key(input, keycode, 0);
> +               input_sync(input);
> +               break;
> +       }
>
>         acpi_bus_generate_netlink_event(button->class, dev_name(&device->dev),
>                                         event, ++button->pushed);
> diff --git a/include/acpi/button.h b/include/acpi/button.h
> index af2fce5d2ee3..832f1a308828 100644
> --- a/include/acpi/button.h
> +++ b/include/acpi/button.h
> @@ -6,6 +6,10 @@
>  #define ACPI_BUTTON_HID_LID    "PNP0C0D"
>  #define ACPI_BUTTON_HID_SLEEP  "PNP0C0E"
>
> +#define ACPI_BUTTON_NOTIFY_STATUS      0x80
> +#define ACPI_BUTTON_NOTIFY_PRESS       0x81
> +#define ACPI_BUTTON_NOTIFY_RELEASE     0x82
> +
>  #if IS_ENABLED(CONFIG_ACPI_BUTTON)
>  extern int acpi_lid_open(void);
>  #else
> --
> 2.25.1
>
>
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