diff mbox series

PM: domains: Don't runtime resume devices at genpd_prepare()

Message ID 20210304192843.216829-1-ulf.hansson@linaro.org (mailing list archive)
State Awaiting Upstream
Delegated to: Rafael Wysocki
Headers show
Series PM: domains: Don't runtime resume devices at genpd_prepare() | expand

Commit Message

Ulf Hansson March 4, 2021, 7:28 p.m. UTC
Runtime resuming a device upfront in the genpd_prepare() callback, to check
if there is a wakeup pending for it, seems like an unnecessary thing to do.
The PM core already manages these kind of things in a common way in
__device_suspend(), via calling pm_runtime_barrier() and
pm_wakeup_pending().

Therefore, let's simply drop this behaviour from genpd_prepare().

Note that, this change is applicable only for devices that are attached to
a genpd that has the GENPD_FLAG_ACTIVE_WAKEUP set (Renesas, Mediatek, and
Rockchip platforms). Moreover, a driver that needs to restore power for its
device to re-configure it for a system wakeup, may still call
pm_runtime_get_sync(), for example, to do this.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
 drivers/base/power/domain.c | 36 ------------------------------------
 1 file changed, 36 deletions(-)

Comments

Rafael J. Wysocki March 18, 2021, 6:40 p.m. UTC | #1
On Thu, Mar 4, 2021 at 8:30 PM Ulf Hansson <ulf.hansson@linaro.org> wrote:
>
> Runtime resuming a device upfront in the genpd_prepare() callback, to check
> if there is a wakeup pending for it, seems like an unnecessary thing to do.
> The PM core already manages these kind of things in a common way in
> __device_suspend(), via calling pm_runtime_barrier() and
> pm_wakeup_pending().
>
> Therefore, let's simply drop this behaviour from genpd_prepare().
>
> Note that, this change is applicable only for devices that are attached to
> a genpd that has the GENPD_FLAG_ACTIVE_WAKEUP set (Renesas, Mediatek, and
> Rockchip platforms). Moreover, a driver that needs to restore power for its
> device to re-configure it for a system wakeup, may still call
> pm_runtime_get_sync(), for example, to do this.
>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> ---
>  drivers/base/power/domain.c | 36 ------------------------------------
>  1 file changed, 36 deletions(-)
>
> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
> index 78c310d3179d..b6a782c31613 100644
> --- a/drivers/base/power/domain.c
> +++ b/drivers/base/power/domain.c
> @@ -1087,34 +1087,6 @@ static void genpd_sync_power_on(struct generic_pm_domain *genpd, bool use_lock,
>         genpd->status = GENPD_STATE_ON;
>  }
>
> -/**
> - * resume_needed - Check whether to resume a device before system suspend.
> - * @dev: Device to check.
> - * @genpd: PM domain the device belongs to.
> - *
> - * There are two cases in which a device that can wake up the system from sleep
> - * states should be resumed by genpd_prepare(): (1) if the device is enabled
> - * to wake up the system and it has to remain active for this purpose while the
> - * system is in the sleep state and (2) if the device is not enabled to wake up
> - * the system from sleep states and it generally doesn't generate wakeup signals
> - * by itself (those signals are generated on its behalf by other parts of the
> - * system).  In the latter case it may be necessary to reconfigure the device's
> - * wakeup settings during system suspend, because it may have been set up to
> - * signal remote wakeup from the system's working state as needed by runtime PM.
> - * Return 'true' in either of the above cases.
> - */
> -static bool resume_needed(struct device *dev,
> -                         const struct generic_pm_domain *genpd)
> -{
> -       bool active_wakeup;
> -
> -       if (!device_can_wakeup(dev))
> -               return false;
> -
> -       active_wakeup = genpd_is_active_wakeup(genpd);
> -       return device_may_wakeup(dev) ? active_wakeup : !active_wakeup;
> -}
> -
>  /**
>   * genpd_prepare - Start power transition of a device in a PM domain.
>   * @dev: Device to start the transition of.
> @@ -1135,14 +1107,6 @@ static int genpd_prepare(struct device *dev)
>         if (IS_ERR(genpd))
>                 return -EINVAL;
>
> -       /*
> -        * If a wakeup request is pending for the device, it should be woken up
> -        * at this point and a system wakeup event should be reported if it's
> -        * set up to wake up the system from sleep states.
> -        */
> -       if (resume_needed(dev, genpd))
> -               pm_runtime_resume(dev);
> -
>         genpd_lock(genpd);
>
>         if (genpd->prepared_count++ == 0)
> --

Applied as 5.13 material, thanks!
diff mbox series

Patch

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 78c310d3179d..b6a782c31613 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -1087,34 +1087,6 @@  static void genpd_sync_power_on(struct generic_pm_domain *genpd, bool use_lock,
 	genpd->status = GENPD_STATE_ON;
 }
 
-/**
- * resume_needed - Check whether to resume a device before system suspend.
- * @dev: Device to check.
- * @genpd: PM domain the device belongs to.
- *
- * There are two cases in which a device that can wake up the system from sleep
- * states should be resumed by genpd_prepare(): (1) if the device is enabled
- * to wake up the system and it has to remain active for this purpose while the
- * system is in the sleep state and (2) if the device is not enabled to wake up
- * the system from sleep states and it generally doesn't generate wakeup signals
- * by itself (those signals are generated on its behalf by other parts of the
- * system).  In the latter case it may be necessary to reconfigure the device's
- * wakeup settings during system suspend, because it may have been set up to
- * signal remote wakeup from the system's working state as needed by runtime PM.
- * Return 'true' in either of the above cases.
- */
-static bool resume_needed(struct device *dev,
-			  const struct generic_pm_domain *genpd)
-{
-	bool active_wakeup;
-
-	if (!device_can_wakeup(dev))
-		return false;
-
-	active_wakeup = genpd_is_active_wakeup(genpd);
-	return device_may_wakeup(dev) ? active_wakeup : !active_wakeup;
-}
-
 /**
  * genpd_prepare - Start power transition of a device in a PM domain.
  * @dev: Device to start the transition of.
@@ -1135,14 +1107,6 @@  static int genpd_prepare(struct device *dev)
 	if (IS_ERR(genpd))
 		return -EINVAL;
 
-	/*
-	 * If a wakeup request is pending for the device, it should be woken up
-	 * at this point and a system wakeup event should be reported if it's
-	 * set up to wake up the system from sleep states.
-	 */
-	if (resume_needed(dev, genpd))
-		pm_runtime_resume(dev);
-
 	genpd_lock(genpd);
 
 	if (genpd->prepared_count++ == 0)