[PATCH 022/106] PM / Sleep: avoid 'autosleep' in shutdown progress

From: Luis Henriques
Date: Tue Jul 30 2013 - 05:58:01 EST -stable review patch. If anyone has any objections, please let me know.


From: Liu ShuoX <shuox.liu@xxxxxxxxx>

commit e5248a111bf4048a9f3fab1a9c94c4630a10592a upstream.

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@xxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
kernel/power/autosleep.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/power/autosleep.c b/kernel/power/autosleep.c
index ca304046..ab79ecb 100644
--- a/kernel/power/autosleep.c
+++ b/kernel/power/autosleep.c
@@ -32,7 +32,8 @@ static void try_to_suspend(struct work_struct *work)


- if (!pm_save_wakeup_count(initial_count)) {
+ if (!pm_save_wakeup_count(initial_count) ||
+ system_state != SYSTEM_RUNNING) {
goto out;

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