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Diffstat (limited to 'sound/core')
-rw-r--r--sound/core/init.c23
-rw-r--r--sound/core/oss/mixer_oss.c16
-rw-r--r--sound/core/sound.c5
3 files changed, 37 insertions, 7 deletions
diff --git a/sound/core/init.c b/sound/core/init.c
index 0c4dc40376a7..356d41e4f3a4 100644
--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -49,8 +49,7 @@ static const struct file_operations snd_shutdown_f_ops;
/* locked for registering/using */
static DECLARE_BITMAP(snd_cards_lock, SNDRV_CARDS);
-struct snd_card *snd_cards[SNDRV_CARDS];
-EXPORT_SYMBOL(snd_cards);
+static struct snd_card *snd_cards[SNDRV_CARDS];
static DEFINE_MUTEX(snd_card_mutex);
@@ -268,6 +267,26 @@ int snd_card_new(struct device *parent, int idx, const char *xid,
}
EXPORT_SYMBOL(snd_card_new);
+/**
+ * snd_card_ref - Get the card object from the index
+ * @idx: the card index
+ *
+ * Returns a card object corresponding to the given index or NULL if not found.
+ * Release the object via snd_card_unref().
+ */
+struct snd_card *snd_card_ref(int idx)
+{
+ struct snd_card *card;
+
+ mutex_lock(&snd_card_mutex);
+ card = snd_cards[idx];
+ if (card)
+ get_device(&card->card_dev);
+ mutex_unlock(&snd_card_mutex);
+ return card;
+}
+EXPORT_SYMBOL_GPL(snd_card_ref);
+
/* return non-zero if a card is already locked */
int snd_card_locked(int card)
{
diff --git a/sound/core/oss/mixer_oss.c b/sound/core/oss/mixer_oss.c
index 64d904bee8bb..c8618678649c 100644
--- a/sound/core/oss/mixer_oss.c
+++ b/sound/core/oss/mixer_oss.c
@@ -1403,24 +1403,32 @@ static int snd_mixer_oss_notify_handler(struct snd_card *card, int cmd)
static int __init alsa_mixer_oss_init(void)
{
+ struct snd_card *card;
int idx;
snd_mixer_oss_notify_callback = snd_mixer_oss_notify_handler;
for (idx = 0; idx < SNDRV_CARDS; idx++) {
- if (snd_cards[idx])
- snd_mixer_oss_notify_handler(snd_cards[idx], SND_MIXER_OSS_NOTIFY_REGISTER);
+ card = snd_card_ref(idx);
+ if (card) {
+ snd_mixer_oss_notify_handler(card, SND_MIXER_OSS_NOTIFY_REGISTER);
+ snd_card_unref(card);
+ }
}
return 0;
}
static void __exit alsa_mixer_oss_exit(void)
{
+ struct snd_card *card;
int idx;
snd_mixer_oss_notify_callback = NULL;
for (idx = 0; idx < SNDRV_CARDS; idx++) {
- if (snd_cards[idx])
- snd_mixer_oss_notify_handler(snd_cards[idx], SND_MIXER_OSS_NOTIFY_FREE);
+ card = snd_card_ref(idx);
+ if (card) {
+ snd_mixer_oss_notify_handler(card, SND_MIXER_OSS_NOTIFY_FREE);
+ snd_card_unref(card);
+ }
}
}
diff --git a/sound/core/sound.c b/sound/core/sound.c
index b30f027eb0fe..a9ad4379523b 100644
--- a/sound/core/sound.c
+++ b/sound/core/sound.c
@@ -134,8 +134,11 @@ static struct snd_minor *autoload_device(unsigned int minor)
if (dev == SNDRV_MINOR_CONTROL) {
/* /dev/aloadC? */
int card = SNDRV_MINOR_CARD(minor);
- if (snd_cards[card] == NULL)
+ struct snd_card *ref = snd_card_ref(card);
+ if (!ref)
snd_request_card(card);
+ else
+ snd_card_unref(ref);
} else if (dev == SNDRV_MINOR_GLOBAL) {
/* /dev/aloadSEQ */
snd_request_other(minor);