Commit e5248a11 authored Jul 11, 2013 by Liu ShuoX Committed by Rafael J. Wysocki Jul 15, 2013

PM / Sleep: avoid 'autosleep' in shutdown progress



Prevent automatic system suspend from happening during system
shutdown by making try_to_suspend() check system_state and return
immediately if it is not SYSTEM_RUNNING.

This prevents the following breakage from happening (scenario from
Zhang Yanmin):

 Kernel starts shutdown and calls all device driver's shutdown
 callback.  When a driver's shutdown is called, the last wakelock is
 released and suspend-to-ram starts.  However, as some driver's shut
 down callbacks already shut down devices and disabled runtime pm,
 the suspend-to-ram calls driver's suspend callback without noticing
 that device is already off and causes crash.

[rjw: Changelog]
Signed-off-by: Liu ShuoX <shuox.liu@intel.com>
Cc: 3.5+ <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

parent aae760ed

kernel/power/autosleep.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -32,7 +32,8 @@ static void try_to_suspend(struct work_struct *work)

		mutex_lock(&autosleep_lock);

		if (!pm_save_wakeup_count(initial_count)) {
		if (!pm_save_wakeup_count(initial_count) \|\|
		system_state != SYSTEM_RUNNING) {
		mutex_unlock(&autosleep_lock);
		goto out;
		}

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