Merge tag 'pull_req_20121126' of git://git.kernel.org/pub/scm/linux/kernel/git/mzx/devfreq into pm-devfreq

Pull devfreq changes from MyungJoo Ham.

* tag 'pull_req_20121126' of git://git.kernel.org/pub/scm/linux/kernel/git/mzx/devfreq:
  PM / devfreq: Fix return value in devfreq_remove_governor()
  PM / devfreq: Fix incorrect argument in error message
  PM / devfreq: missing rcu_read_lock() added for find_device_opp()
  PM / devfreq: remove compiler error when a governor is module

drivers/devfreq/devfreq.c

@@ -643,8 +643,8 @@ int devfreq_remove_governor(struct devfreq_governor *governor)
 	g = find_devfreq_governor(governor->name);
 	if (IS_ERR(g)) {
 		pr_err("%s: governor %s not registered\n", __func__,
-		       g->name);
-		err = -EINVAL;
+		       governor->name);
+		err = PTR_ERR(g);
 		goto err_out;
 	}
 	list_for_each_entry(devfreq, &devfreq_list, node) {
@@ -1023,11 +1023,18 @@ struct opp *devfreq_recommended_opp(struct device *dev, unsigned long *freq,
  */
 int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq)
 {
-	struct srcu_notifier_head *nh = opp_get_notifier(dev);
+	struct srcu_notifier_head *nh;
+	int ret = 0;
 
+	rcu_read_lock();
+	nh = opp_get_notifier(dev);
 	if (IS_ERR(nh))
-		return PTR_ERR(nh);
-	return srcu_notifier_chain_register(nh, &devfreq->nb);
+		ret = PTR_ERR(nh);
+	rcu_read_unlock();
+	if (!ret)
+		ret = srcu_notifier_chain_register(nh, &devfreq->nb);
+
+	return ret;
 }
 
 /**
@@ -1042,11 +1049,18 @@ int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq)
  */
 int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq)
 {
-	struct srcu_notifier_head *nh = opp_get_notifier(dev);
+	struct srcu_notifier_head *nh;
+	int ret = 0;
 
+	rcu_read_lock();
+	nh = opp_get_notifier(dev);
 	if (IS_ERR(nh))
-		return PTR_ERR(nh);
-	return srcu_notifier_chain_unregister(nh, &devfreq->nb);
+		ret = PTR_ERR(nh);
+	rcu_read_unlock();
+	if (!ret)
+		ret = srcu_notifier_chain_unregister(nh, &devfreq->nb);
+
+	return ret;
 }
 
 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");

include/linux/devfreq.h

@@ -192,7 +192,7 @@ extern int devfreq_register_opp_notifier(struct device *dev,
 extern int devfreq_unregister_opp_notifier(struct device *dev,
 					   struct devfreq *devfreq);
 
-#ifdef CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND
+#if IS_ENABLED(CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND)
 /**
  * struct devfreq_simple_ondemand_data - void *data fed to struct devfreq
  *	and devfreq_add_device