PM / Sleep: Prevent waiting forever on asynchronous suspend after abort
Mandeep Singh Baines [Sun, 24 Jun 2012 21:31:09 +0000 (23:31 +0200)]
commit 1f758b23177d588a71b96ad02990e715949bb82f upstream.

__device_suspend() must always send a completion. Otherwise, parent
devices will wait forever.

Commit 1e2ef05b, "PM: Limit race conditions between runtime PM and
system sleep (v2)", introduced a regression by short-circuiting the
complete_all() for certain error cases.

This patch fixes the bug by always signalling a completion.

Addresses http://crosbug.com/31972

Tested by injecting an abort.

Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/power/main.c

index b462c0e..3085f9b 100644 (file)
@@ -1021,7 +1021,7 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async)
        dpm_wait_for_children(dev, async);
 
        if (async_error)
-               return 0;
+               goto Complete;
 
        pm_runtime_get_noresume(dev);
        if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
@@ -1030,7 +1030,7 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async)
        if (pm_wakeup_pending()) {
                pm_runtime_put_sync(dev);
                async_error = -EBUSY;
-               return 0;
+               goto Complete;
        }
 
        device_lock(dev);
@@ -1087,6 +1087,8 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async)
        }
 
        device_unlock(dev);
+
+ Complete:
        complete_all(&dev->power.completion);
 
        if (error) {