PM / Sleep: avoid 'autosleep' in shutdown progress
authorLiu ShuoX <shuox.liu@intel.com>
Thu, 11 Jul 2013 08:03:45 +0000 (16:03 +0800)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Sun, 14 Jul 2013 23:31:37 +0000 (01:31 +0200)
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>
kernel/power/autosleep.c

index c6422ff..9012ecf 100644 (file)
@@ -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;
        }