[PATCH v2 02/11] thermal: core: Add and use a reverse thermal zone guard

["Rafael J. Wysocki" <rjw@rjwysocki.net>]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Add a guard for unlocking a locked thermal zone temporarily and use it
in thermal_zone_pm_prepare().

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---

This is a new patch

---
 drivers/thermal/thermal_core.c |    8 +++-----
 drivers/thermal/thermal_core.h |    3 +++
 2 files changed, 6 insertions(+), 5 deletions(-)

Index: linux-pm/drivers/thermal/thermal_core.c
===================================================================
--- linux-pm.orig/drivers/thermal/thermal_core.c
+++ linux-pm/drivers/thermal/thermal_core.c
@@ -1702,11 +1702,9 @@ static void thermal_zone_pm_prepare(stru
 		 * acquired the lock yet, so release it to let the function run
 		 * and wait util it has done the work.
 		 */
-		mutex_unlock(&tz->lock);
-
-		wait_for_completion(&tz->resume);
-
-		mutex_lock(&tz->lock);
+		scoped_guard(thermal_zone_reverse, tz) {
+			wait_for_completion(&tz->resume);
+		}
 	}
 
 	tz->state |= TZ_STATE_FLAG_SUSPENDED;
Index: linux-pm/drivers/thermal/thermal_core.h
===================================================================
--- linux-pm.orig/drivers/thermal/thermal_core.h
+++ linux-pm/drivers/thermal/thermal_core.h
@@ -148,6 +148,9 @@ struct thermal_zone_device {
 DEFINE_GUARD(thermal_zone, struct thermal_zone_device *, mutex_lock(&_T->lock),
 	     mutex_unlock(&_T->lock))
 
+DEFINE_GUARD(thermal_zone_reverse, struct thermal_zone_device *,
+	     mutex_unlock(&_T->lock), mutex_lock(&_T->lock))
+
 /* Initial thermal zone temperature. */
 #define THERMAL_TEMP_INIT	INT_MIN