2021-10-22 13:01:04

by Rafael J. Wysocki

Subject: [PATCH] PM: sleep: Do not let "syscore" devices runtime-suspend during system transitions

From: Rafael J. Wysocki <[email protected]>

There is no reason to allow "syscore" devices to runtime-suspend
during system-wide PM transitions, because they are subject to the
same possible failure modes as any other devices in that respect.

Accordingly, change device_prepare() and device_complete() to call
pm_runtime_get_noresume() and pm_runtime_put(), respectively, for
"syscore" devices too.

Fixes: 057d51a1268f ("Merge branch 'pm-sleep'")
Signed-off-by: Rafael J. Wysocki <[email protected]>
Cc: 3.10+ <[email protected]> # 3.10+
---
drivers/base/power/main.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

Index: linux-pm/drivers/base/power/main.c
===================================================================
--- linux-pm.orig/drivers/base/power/main.c
+++ linux-pm/drivers/base/power/main.c
@@ -1048,7 +1048,7 @@ static void device_complete(struct devic
const char *info = NULL;

if (dev->power.syscore)
- return;
+ goto out;

device_lock(dev);

@@ -1078,6 +1078,7 @@ static void device_complete(struct devic

device_unlock(dev);

+out:
pm_runtime_put(dev);
}

@@ -1789,9 +1790,6 @@ static int device_prepare(struct device
int (*callback)(struct device *) = NULL;
int ret = 0;

- if (dev->power.syscore)
- return 0;
-
/*
* If a device's parent goes into runtime suspend at the wrong time,
* it won't be possible to resume the device. To prevent this we
@@ -1800,6 +1798,9 @@ static int device_prepare(struct device
*/
pm_runtime_get_noresume(dev);

+ if (dev->power.syscore)
+ return 0;
+
device_lock(dev);

dev->power.wakeup_path = false;

2021-10-22 14:01:28

by Ulf Hansson

Subject: Re: [PATCH] PM: sleep: Do not let "syscore" devices runtime-suspend during system transitions

On Fri, 22 Oct 2021 at 14:58, Rafael J. Wysocki <[email protected]> wrote:
>
> From: Rafael J. Wysocki <[email protected]>
>
> There is no reason to allow "syscore" devices to runtime-suspend
> during system-wide PM transitions, because they are subject to the
> same possible failure modes as any other devices in that respect.
>
> Accordingly, change device_prepare() and device_complete() to call
> pm_runtime_get_noresume() and pm_runtime_put(), respectively, for
> "syscore" devices too.
>
> Fixes: 057d51a1268f ("Merge branch 'pm-sleep'")
> Signed-off-by: Rafael J. Wysocki <[email protected]>
> Cc: 3.10+ <[email protected]> # 3.10+

This makes perfect sense for me too.

Reviewed-by: Ulf Hansson <[email protected]>

Kind regards
Uffe

> ---
> drivers/base/power/main.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
> Index: linux-pm/drivers/base/power/main.c
> ===================================================================
> --- linux-pm.orig/drivers/base/power/main.c
> +++ linux-pm/drivers/base/power/main.c
> @@ -1048,7 +1048,7 @@ static void device_complete(struct devic
> const char *info = NULL;
>
> if (dev->power.syscore)
> - return;
> + goto out;
>
> device_lock(dev);
>
> @@ -1078,6 +1078,7 @@ static void device_complete(struct devic
>
> device_unlock(dev);
>
> +out:
> pm_runtime_put(dev);
> }
>
> @@ -1789,9 +1790,6 @@ static int device_prepare(struct device
> int (*callback)(struct device *) = NULL;
> int ret = 0;
>
> - if (dev->power.syscore)
> - return 0;
> -
> /*
> * If a device's parent goes into runtime suspend at the wrong time,
> * it won't be possible to resume the device. To prevent this we
> @@ -1800,6 +1798,9 @@ static int device_prepare(struct device
> */
> pm_runtime_get_noresume(dev);
>
> + if (dev->power.syscore)
> + return 0;
> +
> device_lock(dev);
>
> dev->power.wakeup_path = false;
>
>
>