thermal: core: Allow orderly_poweroff to be called only once

thermal_zone_device_check --> thermal_zone_device_update -->
handle_thermal_trip --> handle_critical_trips --> orderly_poweroff

The above sequence happens every 250/500 mS based on the configuration.
The orderly_poweroff function is getting called every 250/500 mS.
With a full fledged file system it takes at least 5-10 Seconds to
power off gracefully.

In that period due to the thermal_zone_device_check triggering
periodically the thermal work queues bombard with
orderly_poweroff calls multiple times eventually leading to
failures in gracefully powering off the system.

Make sure that orderly_poweroff is called only once.
Signed-off-by: Keerthy <j-keerthy@ti.com>
Acked-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

drivers/thermal/thermal_core.c

@@ -45,8 +45,10 @@ static LIST_HEAD(thermal_governor_list);
 
 static DEFINE_MUTEX(thermal_list_lock);
 static DEFINE_MUTEX(thermal_governor_lock);
+static DEFINE_MUTEX(poweroff_lock);
 
 static atomic_t in_suspend;
+static bool power_off_triggered;
 
 static struct thermal_governor *def_governor;
 
@@ -342,7 +344,12 @@ static void handle_critical_trips(struct thermal_zone_device *tz,
 		dev_emerg(&tz->device,
 			  "critical temperature reached(%d C),shutting down\n",
 			  tz->temperature / 1000);
-		orderly_poweroff(true);
+		mutex_lock(&poweroff_lock);
+		if (!power_off_triggered) {
+			orderly_poweroff(true);
+			power_off_triggered = true;
+		}
+		mutex_unlock(&poweroff_lock);
 	}
 }
 
@@ -1463,6 +1470,7 @@ static int __init thermal_init(void)
 {
 	int result;
 
+	mutex_init(&poweroff_lock);
 	result = thermal_register_governors();
 	if (result)
 		goto error;
@@ -1497,6 +1505,7 @@ static int __init thermal_init(void)
 	ida_destroy(&thermal_cdev_ida);
 	mutex_destroy(&thermal_list_lock);
 	mutex_destroy(&thermal_governor_lock);
+	mutex_destroy(&poweroff_lock);
 	return result;
 }