1 files changed, 33 insertions, 23 deletions

diff --git a/drivers/thermal/step_wise.c b/drivers/thermal/step_wise.c
index 407cde3211c..f251521baaa 100644
--- a/drivers/thermal/step_wise.c
+++ b/drivers/thermal/step_wise.c
@@ -22,9 +22,6 @@
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  */
 
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include <linux/module.h>
 #include <linux/thermal.h>
 
 #include "thermal_core.h"
@@ -54,38 +51,52 @@ static unsigned long get_target_state(struct thermal_instance *instance,
 {
 	struct thermal_cooling_device *cdev = instance->cdev;
 	unsigned long cur_state;
+	unsigned long next_target;
 
+	/*
+	 * We keep this instance the way it is by default.
+	 * Otherwise, we use the current state of the
+	 * cdev in use to determine the next_target.
+	 */
 	cdev->ops->get_cur_state(cdev, &cur_state);
+	next_target = instance->target;
+	dev_dbg(&cdev->device, "cur_state=%ld\n", cur_state);
 
 	switch (trend) {
 	case THERMAL_TREND_RAISING:
-		if (throttle)
-			cur_state = cur_state < instance->upper ?
+		if (throttle) {
+			next_target = cur_state < instance->upper ?
 				    (cur_state + 1) : instance->upper;
+			if (next_target < instance->lower)
+				next_target = instance->lower;
+		}
 		break;
 	case THERMAL_TREND_RAISE_FULL:
 		if (throttle)
-			cur_state = instance->upper;
+			next_target = instance->upper;
 		break;
 	case THERMAL_TREND_DROPPING:
 		if (cur_state == instance->lower) {
 			if (!throttle)
-				cur_state = -1;
-		} else
-			cur_state -= 1;
+				next_target = THERMAL_NO_TARGET;
+		} else {
+			next_target = cur_state - 1;
+			if (next_target > instance->upper)
+				next_target = instance->upper;
+		}
 		break;
 	case THERMAL_TREND_DROP_FULL:
 		if (cur_state == instance->lower) {
 			if (!throttle)
-				cur_state = -1;
+				next_target = THERMAL_NO_TARGET;
 		} else
-			cur_state = instance->lower;
+			next_target = instance->lower;
 		break;
 	default:
 		break;
 	}
 
-	return cur_state;
+	return next_target;
 }
 
 static void update_passive_instance(struct thermal_zone_device *tz,
@@ -121,6 +132,9 @@ static void thermal_zone_trip_update(struct thermal_zone_device *tz, int trip)
 	if (tz->temperature >= trip_temp)
 		throttle = true;
 
+	dev_dbg(&tz->device, "Trip%d[type=%d,temp=%ld]:trend=%d,throttle=%d\n",
+				trip, trip_type, trip_temp, trend, throttle);
+
 	mutex_lock(&tz->lock);
 
 	list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
@@ -129,6 +143,11 @@ static void thermal_zone_trip_update(struct thermal_zone_device *tz, int trip)
 
 		old_target = instance->target;
 		instance->target = get_target_state(instance, trend, throttle);
+		dev_dbg(&instance->cdev->device, "old_target=%d, target=%d\n",
+					old_target, (int)instance->target);
+
+		if (old_target == instance->target)
+			continue;
 
 		/* Activate a passive thermal instance */
 		if (old_target == THERMAL_NO_TARGET &&
@@ -180,23 +199,14 @@ static int step_wise_throttle(struct thermal_zone_device *tz, int trip)
 static struct thermal_governor thermal_gov_step_wise = {
 	.name		= "step_wise",
 	.throttle	= step_wise_throttle,
-	.owner		= THIS_MODULE,
 };
 
-static int __init thermal_gov_step_wise_init(void)
+int thermal_gov_step_wise_register(void)
 {
 	return thermal_register_governor(&thermal_gov_step_wise);
 }
 
-static void __exit thermal_gov_step_wise_exit(void)
+void thermal_gov_step_wise_unregister(void)
 {
 	thermal_unregister_governor(&thermal_gov_step_wise);
 }
-
-/* This should load after thermal framework */
-fs_initcall(thermal_gov_step_wise_init);
-module_exit(thermal_gov_step_wise_exit);
-
-MODULE_AUTHOR("Durgadoss R");
-MODULE_DESCRIPTION("A step-by-step thermal throttling governor");
-MODULE_LICENSE("GPL");