1 files changed, 9 insertions, 2 deletions

diff --git a/sound/core/sound.c b/sound/core/sound.c
index 643976000ce8..89780c323f19 100644
--- a/sound/core/sound.c
+++ b/sound/core/sound.c
@@ -98,6 +98,10 @@ static void snd_request_other(int minor)
  *
  * Checks that a minor device with the specified type is registered, and returns
  * its user data pointer.
+ *
+ * This function increments the reference counter of the card instance
+ * if an associated instance with the given minor number and type is found.
+ * The caller must call snd_card_unref() appropriately later.
  */
 void *snd_lookup_minor_data(unsigned int minor, int type)
 {
@@ -108,9 +112,11 @@ void *snd_lookup_minor_data(unsigned int minor, int type)
                 return NULL;
         mutex_lock(&sound_mutex);
         mreg = snd_minors[minor];
-        if (mreg && mreg->type == type)
+        if (mreg && mreg->type == type) {
                 private_data = mreg->private_data;
-        else
+                if (mreg->card_ptr)
+                        atomic_inc(&mreg->card_ptr->refcount);
+        } else
                 private_data = NULL;
         mutex_unlock(&sound_mutex);
         return private_data;
@@ -275,6 +281,7 @@ int snd_register_device_for_dev(int type, struct snd_card *card, int dev,
         preg->device = dev;
         preg->f_ops = f_ops;
         preg->private_data = private_data;
+        preg->card_ptr = card;
         mutex_lock(&sound_mutex);
 #ifdef CONFIG_SND_DYNAMIC_MINORS
         minor = snd_find_free_minor(type);