2 files changed, 15 insertions, 1 deletions

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 9aae767bf39b..ba08b5521382 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -1341,6 +1341,7 @@ int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
         if (!result) {
                 list_add_tail(&dev->tz_node, &tz->thermal_instances);
                 list_add_tail(&dev->cdev_node, &cdev->thermal_instances);
+                atomic_set(&tz->need_update, 1);
         }
         mutex_unlock(&cdev->lock);
         mutex_unlock(&tz->lock);
@@ -1450,6 +1451,7 @@ __thermal_cooling_device_register(struct device_node *np,
                                   const struct thermal_cooling_device_ops *ops)
 {
         struct thermal_cooling_device *cdev;
+        struct thermal_zone_device *pos = NULL;
         int result;
 
         if (type && strlen(type) >= THERMAL_NAME_LENGTH)
@@ -1494,6 +1496,12 @@ __thermal_cooling_device_register(struct device_node *np,
         /* Update binding information for 'this' new cdev */
         bind_cdev(cdev);
 
+        mutex_lock(&thermal_list_lock);
+        list_for_each_entry(pos, &thermal_tz_list, node)
+                if (atomic_cmpxchg(&pos->need_update, 1, 0))
+                        thermal_zone_device_update(pos);
+        mutex_unlock(&thermal_list_lock);
+
         return cdev;
 }
 
@@ -1826,6 +1834,8 @@ struct thermal_zone_device *thermal_zone_device_register(const char *type,
         tz->trips = trips;
         tz->passive_delay = passive_delay;
         tz->polling_delay = polling_delay;
+        /* A new thermal zone needs to be updated anyway. */
+        atomic_set(&tz->need_update, 1);
 
         dev_set_name(&tz->device, "thermal_zone%d", tz->id);
         result = device_register(&tz->device);
@@ -1921,7 +1931,9 @@ struct thermal_zone_device *thermal_zone_device_register(const char *type,
         INIT_DELAYED_WORK(&(tz->poll_queue), thermal_zone_device_check);
 
         thermal_zone_device_reset(tz);
-        thermal_zone_device_update(tz);
+        /* Update the new thermal zone and mark it as already updated. */
+        if (atomic_cmpxchg(&tz->need_update, 1, 0))
+                thermal_zone_device_update(tz);
 
         return tz;
 
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index 103fcbe6bdaf..e13a1ace50e9 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -170,6 +170,7 @@ struct thermal_attr {
  * @forced_passive:     If > 0, temperature at which to switch on all ACPI
  *                      processor cooling devices.  Currently only used by the
  *                      step-wise governor.
+ * @need_update:        if equals 1, thermal_zone_device_update needs to be invoked.
  * @ops:        operations this &thermal_zone_device supports
  * @tzp:        thermal zone parameters
  * @governor:   pointer to the governor for this thermal zone
@@ -197,6 +198,7 @@ struct thermal_zone_device {
         int emul_temperature;
         int passive;
         unsigned int forced_passive;
+        atomic_t need_update;
         struct thermal_zone_device_ops *ops;
         struct thermal_zone_params *tzp;
         struct thermal_governor *governor;