diff options
Diffstat (limited to 'sound/core/sound.c')
| -rw-r--r-- | sound/core/sound.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/sound/core/sound.c b/sound/core/sound.c index 28f35593a75..7c0640eeee5 100644 --- 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 (mreg->card_ptr) + atomic_inc(&mreg->card_ptr->refcount); + } else private_data = NULL; mutex_unlock(&sound_mutex); return private_data; @@ -276,6 +282,7 @@ 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); |