1 files changed, 37 insertions, 26 deletions

diff --git a/sound/core/timer.c b/sound/core/timer.c
index 2c0f292226d7..161ab19cb722 100644
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -240,7 +240,8 @@ static int snd_timer_check_master(struct snd_timer_instance *master)
 	return 0;
 }
 
-static int snd_timer_close_locked(struct snd_timer_instance *timeri);
+static int snd_timer_close_locked(struct snd_timer_instance *timeri,
+				  struct device **card_devp_to_put);
 
 /*
  * open a timer instance
@@ -252,21 +253,23 @@ int snd_timer_open(struct snd_timer_instance **ti,
 {
 	struct snd_timer *timer;
 	struct snd_timer_instance *timeri = NULL;
+	struct device *card_dev_to_put = NULL;
 	int err;
 
+	mutex_lock(&register_mutex);
 	if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
 		/* open a slave instance */
 		if (tid->dev_sclass <= SNDRV_TIMER_SCLASS_NONE ||
 		    tid->dev_sclass > SNDRV_TIMER_SCLASS_OSS_SEQUENCER) {
 			pr_debug("ALSA: timer: invalid slave class %i\n",
 				 tid->dev_sclass);
-			return -EINVAL;
+			err = -EINVAL;
+			goto unlock;
 		}
-		mutex_lock(&register_mutex);
 		timeri = snd_timer_instance_new(owner, NULL);
 		if (!timeri) {
-			mutex_unlock(&register_mutex);
-			return -ENOMEM;
+			err = -ENOMEM;
+			goto unlock;
 		}
 		timeri->slave_class = tid->dev_sclass;
 		timeri->slave_id = tid->device;
@@ -274,16 +277,13 @@ int snd_timer_open(struct snd_timer_instance **ti,
 		list_add_tail(&timeri->open_list, &snd_timer_slave_list);
 		err = snd_timer_check_slave(timeri);
 		if (err < 0) {
-			snd_timer_close_locked(timeri);
+			snd_timer_close_locked(timeri, &card_dev_to_put);
 			timeri = NULL;
 		}
-		mutex_unlock(&register_mutex);
-		*ti = timeri;
-		return err;
+		goto unlock;
 	}
 
 	/* open a master instance */
-	mutex_lock(&register_mutex);
 	timer = snd_timer_find(tid);
 #ifdef CONFIG_MODULES
 	if (!timer) {
@@ -294,25 +294,26 @@ int snd_timer_open(struct snd_timer_instance **ti,
 	}
 #endif
 	if (!timer) {
-		mutex_unlock(&register_mutex);
-		return -ENODEV;
+		err = -ENODEV;
+		goto unlock;
 	}
 	if (!list_empty(&timer->open_list_head)) {
 		timeri = list_entry(timer->open_list_head.next,
 				    struct snd_timer_instance, open_list);
 		if (timeri->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
-			mutex_unlock(&register_mutex);
-			return -EBUSY;
+			err = -EBUSY;
+			timeri = NULL;
+			goto unlock;
 		}
 	}
 	if (timer->num_instances >= timer->max_instances) {
-		mutex_unlock(&register_mutex);
-		return -EBUSY;
+		err = -EBUSY;
+		goto unlock;
 	}
 	timeri = snd_timer_instance_new(owner, timer);
 	if (!timeri) {
-		mutex_unlock(&register_mutex);
-		return -ENOMEM;
+		err = -ENOMEM;
+		goto unlock;
 	}
 	/* take a card refcount for safe disconnection */
 	if (timer->card)
@@ -321,16 +322,16 @@ int snd_timer_open(struct snd_timer_instance **ti,
 	timeri->slave_id = slave_id;
 
 	if (list_empty(&timer->open_list_head) && timer->hw.open) {
-		int err = timer->hw.open(timer);
+		err = timer->hw.open(timer);
 		if (err) {
 			kfree(timeri->owner);
 			kfree(timeri);
+			timeri = NULL;
 
 			if (timer->card)
-				put_device(&timer->card->card_dev);
+				card_dev_to_put = &timer->card->card_dev;
 			module_put(timer->module);
-			mutex_unlock(&register_mutex);
-			return err;
+			goto unlock;
 		}
 	}
 
@@ -338,10 +339,15 @@ int snd_timer_open(struct snd_timer_instance **ti,
 	timer->num_instances++;
 	err = snd_timer_check_master(timeri);
 	if (err < 0) {
-		snd_timer_close_locked(timeri);
+		snd_timer_close_locked(timeri, &card_dev_to_put);
 		timeri = NULL;
 	}
+
+ unlock:
 	mutex_unlock(&register_mutex);
+	/* put_device() is called after unlock for avoiding deadlock */
+	if (card_dev_to_put)
+		put_device(card_dev_to_put);
 	*ti = timeri;
 	return err;
 }
@@ -351,7 +357,8 @@ EXPORT_SYMBOL(snd_timer_open);
  * close a timer instance
  * call this with register_mutex down.
  */
-static int snd_timer_close_locked(struct snd_timer_instance *timeri)
+static int snd_timer_close_locked(struct snd_timer_instance *timeri,
+				  struct device **card_devp_to_put)
 {
 	struct snd_timer *timer = NULL;
 	struct snd_timer_instance *slave, *tmp;
@@ -403,7 +410,7 @@ static int snd_timer_close_locked(struct snd_timer_instance *timeri)
 			timer->hw.close(timer);
 		/* release a card refcount for safe disconnection */
 		if (timer->card)
-			put_device(&timer->card->card_dev);
+			*card_devp_to_put = &timer->card->card_dev;
 		module_put(timer->module);
 	}
 
@@ -415,14 +422,18 @@ static int snd_timer_close_locked(struct snd_timer_instance *timeri)
  */
 int snd_timer_close(struct snd_timer_instance *timeri)
 {
+	struct device *card_dev_to_put = NULL;
 	int err;
 
 	if (snd_BUG_ON(!timeri))
 		return -ENXIO;
 
 	mutex_lock(&register_mutex);
-	err = snd_timer_close_locked(timeri);
+	err = snd_timer_close_locked(timeri, &card_dev_to_put);
 	mutex_unlock(&register_mutex);
+	/* put_device() is called after unlock for avoiding deadlock */
+	if (card_dev_to_put)
+		put_device(card_dev_to_put);
 	return err;
 }
 EXPORT_SYMBOL(snd_timer_close);