thermal: core: Initialize poll_queue in thermal_zone_device_init()

In preparation for a subsequent change, move the initialization of the
poll_queue delayed work from thermal_zone_device_register_with_trips()
to thermal_zone_device_init() which is called by the former.

However, because thermal_zone_device_init() is also called by
thermal_pm_notify(), make the latter call cancel_delayed_work() on
poll_queue before invoking the former, so as to allow the work
item to be re-initialized safely.

Also move thermal_zone_device_check() which needs to be defined
before thermal_zone_device_init(), so the latter can pass it to the
INIT_DELAYED_WORK() macro.

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

Author: rafaeljw

drivers/thermal/thermal_core.c

@@ -414,9 +414,20 @@ static void update_temperature(struct thermal_zone_device *tz)
 	thermal_genl_sampling_temp(tz->id, temp);
 }
 
+static void thermal_zone_device_check(struct work_struct *work)
+{
+	struct thermal_zone_device *tz = container_of(work, struct
+						      thermal_zone_device,
+						      poll_queue.work);
+	thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
+}
+
 static void thermal_zone_device_init(struct thermal_zone_device *tz)
 {
 	struct thermal_instance *pos;
+
+	INIT_DELAYED_WORK(&tz->poll_queue, thermal_zone_device_check);
+
 	tz->temperature = THERMAL_TEMP_INVALID;
 	tz->prev_low_trip = -INT_MAX;
 	tz->prev_high_trip = INT_MAX;
@@ -513,14 +524,6 @@ void thermal_zone_device_update(struct thermal_zone_device *tz,
 }
 EXPORT_SYMBOL_GPL(thermal_zone_device_update);
 
-static void thermal_zone_device_check(struct work_struct *work)
-{
-	struct thermal_zone_device *tz = container_of(work, struct
-						      thermal_zone_device,
-						      poll_queue.work);
-	thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
-}
-
 int for_each_thermal_governor(int (*cb)(struct thermal_governor *, void *),
 			      void *data)
 {
@@ -1376,8 +1379,6 @@ thermal_zone_device_register_with_trips(const char *type, struct thermal_trip *t
 	/* Bind cooling devices for this zone */
 	bind_tz(tz);
 
-	INIT_DELAYED_WORK(&tz->poll_queue, thermal_zone_device_check);
-
 	thermal_zone_device_init(tz);
 	/* Update the new thermal zone and mark it as already updated. */
 	if (atomic_cmpxchg(&tz->need_update, 1, 0))
@@ -1560,6 +1561,8 @@ static int thermal_pm_notify(struct notifier_block *nb,
 		list_for_each_entry(tz, &thermal_tz_list, node) {
 			mutex_lock(&tz->lock);
 
+			cancel_delayed_work(&tz->poll_queue);
+
 			tz->suspended = false;
 
 			thermal_zone_device_init(tz);