From f2791d733a2f06997b573d1a3cfde21e6f529826 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Mon, 26 Mar 2012 22:46:52 +0200 Subject: [PATCH] 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 CC: Signed-off-by: Rafael J. Wysocki --- drivers/base/power/runtime.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) 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; }