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| author | Alan Stern <stern@rowland.harvard.edu> | 2012-03-26 22:46:52 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rjw@sisk.pl> | 2012-03-26 22:46:52 +0200 |
| commit | f2791d733a2f06997b573d1a3cfde21e6f529826 (patch) | |
| tree | 2af5d3beba35cb4b5a945f148e0a24bbda0ed86f /drivers/base | |
| parent | e22057c8599373e5caef0bc42bdb95d2a361ab0d (diff) | |
| download | lwn-f2791d733a2f06997b573d1a3cfde21e6f529826.tar.gz lwn-f2791d733a2f06997b573d1a3cfde21e6f529826.zip | |
PM / Runtime: don't forget to wake up waitqueue on failure
This patch (as1535) fixes a bug in the runtime PM core. When a
runtime suspend attempt completes, whether successfully or not, the
device's power.wait_queue is supposed to be signalled. But this
doesn't happen in the failure pathway of rpm_suspend() when another
autosuspend attempt is rescheduled. As a result, a task can get stuck
indefinitely on the wait queue (I have seen this happen in testing).
The patch fixes the problem by moving the wake_up_all() call up near
the start of the failure code.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Diffstat (limited to 'drivers/base')
| -rw-r--r-- | drivers/base/power/runtime.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 541f821d4ea6..bd0f3949bcf9 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -532,6 +532,8 @@ static int rpm_suspend(struct device *dev, int rpmflags) dev->power.suspend_time = ktime_set(0, 0); dev->power.max_time_suspended_ns = -1; dev->power.deferred_resume = false; + wake_up_all(&dev->power.wait_queue); + if (retval == -EAGAIN || retval == -EBUSY) { dev->power.runtime_error = 0; @@ -547,7 +549,6 @@ static int rpm_suspend(struct device *dev, int rpmflags) } else { pm_runtime_cancel_pending(dev); } - wake_up_all(&dev->power.wait_queue); goto out; } |