PM / Sleep: Replace mutex_[un]lock(&pm_mutex) with [un]lock_system_sleep()

Using [un]lock_system_sleep() is safer than directly using mutex_[un]lock()
on 'pm_mutex', since the latter could lead to freezing failures. Hence convert
all the present users of mutex_[un]lock(&pm_mutex) to use these safe APIs
instead.

Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

1 files changed, 2 insertions, 2 deletions

diff --git a/kernel/power/main.c b/kernel/power/main.c
index 7d36fb31e4c4..9824b41e5a18 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -116,7 +116,7 @@ static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
         p = memchr(buf, '\n', n);
         len = p ? p - buf : n;
 
-        mutex_lock(&pm_mutex);
+        lock_system_sleep();
 
         level = TEST_FIRST;
         for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++)
@@ -126,7 +126,7 @@ static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
                         break;
                 }
 
-        mutex_unlock(&pm_mutex);
+        unlock_system_sleep();
 
         return error ? error : n;
 }