Merge branch 'stable-3.2' into pandora-3.2

[pandora-kernel.git] / sound / core / sound.c

diff --git a/sound/core/sound.c b/sound/core/sound.c
index 828af35..8e17b4d 100644 (file)
--- a/sound/core/sound.c
+++ b/sound/core/sound.c
@@ -99,6 +99,10 @@ 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)
 {
@@ -109,9 +113,11 @@ 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 (private_data && 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);