Re: [PATCH] ACPI LID: increment wakeup count only when notified.

From: Rafael J. Wysocki
Date: Wed Jun 06 2018 - 03:00:51 EST


On Mon, Jun 4, 2018 at 8:26 PM, Ravi Chandra Sadineni
<ravisadineni@xxxxxxxxxxxx> wrote:
> Currently ACPI LID increments wakeup count irrespective of the wake source.
> This is because we call acpi_lid_initialize_state on every resume.

I don't quite understand the connection between the two sentences
above. Care to clarify?

> Userland deamons using wakeup_count to identify the potential wake
> source for the last wake will be thrown off by this. Instead increment
> the wakeup count only when there is a FIXED_HARDWARE/NOTFIY_STATUS event.
>
> Signed-off-by: Ravi Chandra Sadineni <ravisadineni@xxxxxxxxxxxx>
> ---
> drivers/acpi/button.c | 5 +----
> 1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c
> index f1cc4f9d31cd9..d40fef7241f08 100644
> --- a/drivers/acpi/button.c
> +++ b/drivers/acpi/button.c
> @@ -235,9 +235,6 @@ static int acpi_lid_notify_state(struct acpi_device *device, int state)
> button->last_time = ktime_get();
> }
>
> - if (state)
> - acpi_pm_wakeup_event(&device->dev);
> -
> ret = blocking_notifier_call_chain(&acpi_lid_notifier, state, device);
> if (ret == NOTIFY_DONE)
> ret = blocking_notifier_call_chain(&acpi_lid_notifier, state,
> @@ -417,6 +414,7 @@ static void acpi_button_notify(struct acpi_device *device, u32 event)
> /* fall through */
> case ACPI_BUTTON_NOTIFY_STATUS:
> input = button->input;
> + acpi_pm_wakeup_event(&device->dev);

Not really.

There already is an acpi_pm_wakeup_event() call in the else branch below.

> if (button->type == ACPI_BUTTON_TYPE_LID) {
> mutex_lock(&button->input->mutex);
> users = button->input->users;
> @@ -426,7 +424,6 @@ static void acpi_button_notify(struct acpi_device *device, u32 event)
> } else {
> int keycode;
>
> - acpi_pm_wakeup_event(&device->dev);
> if (button->suspended)
> break;
>
> --