[ALSA] Fix rwlock around snd_iprintf() in sound core
Fixed rwlock around snd_iprintf() in sound core part.
Replaced with mutex.
Also, make mutex and flags static variables with addition of
snd_card_locked() function (just for sound.c).
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/core/init.c b/sound/core/init.c
index 2ff0e5e..38b2d4a 100644
--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -38,11 +38,11 @@
struct snd_shutdown_f_ops *next;
};
-unsigned int snd_cards_lock = 0; /* locked for registering/using */
+static unsigned int snd_cards_lock = 0; /* locked for registering/using */
struct snd_card *snd_cards[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS-1)] = NULL};
EXPORT_SYMBOL(snd_cards);
-DEFINE_RWLOCK(snd_card_rwlock);
+static DEFINE_MUTEX(snd_card_mutex);
#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
@@ -112,7 +112,7 @@
strlcpy(card->id, xid, sizeof(card->id));
}
err = 0;
- write_lock(&snd_card_rwlock);
+ mutex_lock(&snd_card_mutex);
if (idx < 0) {
int idx2;
for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++)
@@ -130,12 +130,12 @@
else
err = -ENODEV;
if (idx < 0 || err < 0) {
- write_unlock(&snd_card_rwlock);
+ mutex_unlock(&snd_card_mutex);
snd_printk(KERN_ERR "cannot find the slot for index %d (range 0-%i)\n", idx, snd_ecards_limit - 1);
goto __error;
}
snd_cards_lock |= 1 << idx; /* lock it */
- write_unlock(&snd_card_rwlock);
+ mutex_unlock(&snd_card_mutex);
card->number = idx;
card->module = module;
INIT_LIST_HEAD(&card->devices);
@@ -173,6 +173,17 @@
EXPORT_SYMBOL(snd_card_new);
+/* return non-zero if a card is already locked */
+int snd_card_locked(int card)
+{
+ int locked;
+
+ mutex_lock(&snd_card_mutex);
+ locked = snd_cards_lock & (1 << card);
+ mutex_unlock(&snd_card_mutex);
+ return locked;
+}
+
static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
{
return -ENODEV;
@@ -240,9 +251,9 @@
spin_unlock(&card->files_lock);
/* phase 1: disable fops (user space) operations for ALSA API */
- write_lock(&snd_card_rwlock);
+ mutex_lock(&snd_card_mutex);
snd_cards[card->number] = NULL;
- write_unlock(&snd_card_rwlock);
+ mutex_unlock(&snd_card_mutex);
/* phase 2: replace file->f_op with special dummy operations */
@@ -321,9 +332,9 @@
if (card == NULL)
return -EINVAL;
- write_lock(&snd_card_rwlock);
+ mutex_lock(&snd_card_mutex);
snd_cards[card->number] = NULL;
- write_unlock(&snd_card_rwlock);
+ mutex_unlock(&snd_card_mutex);
#ifdef CONFIG_PM
wake_up(&card->power_sleep);
@@ -359,9 +370,9 @@
card->s_f_ops = s_f_ops->next;
kfree(s_f_ops);
}
- write_lock(&snd_card_rwlock);
+ mutex_lock(&snd_card_mutex);
snd_cards_lock &= ~(1 << card->number);
- write_unlock(&snd_card_rwlock);
+ mutex_unlock(&snd_card_mutex);
kfree(card);
return 0;
}
@@ -497,16 +508,16 @@
snd_assert(card != NULL, return -EINVAL);
if ((err = snd_device_register_all(card)) < 0)
return err;
- write_lock(&snd_card_rwlock);
+ mutex_lock(&snd_card_mutex);
if (snd_cards[card->number]) {
/* already registered */
- write_unlock(&snd_card_rwlock);
+ mutex_unlock(&snd_card_mutex);
return 0;
}
if (card->id[0] == '\0')
choose_default_id(card);
snd_cards[card->number] = card;
- write_unlock(&snd_card_rwlock);
+ mutex_unlock(&snd_card_mutex);
init_info_for_card(card);
#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
if (snd_mixer_oss_notify_callback)
@@ -527,7 +538,7 @@
struct snd_card *card;
for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
- read_lock(&snd_card_rwlock);
+ mutex_lock(&snd_card_mutex);
if ((card = snd_cards[idx]) != NULL) {
count++;
snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
@@ -538,7 +549,7 @@
snd_iprintf(buffer, " %s\n",
card->longname);
}
- read_unlock(&snd_card_rwlock);
+ mutex_unlock(&snd_card_mutex);
}
if (!count)
snd_iprintf(buffer, "--- no soundcards ---\n");
@@ -552,12 +563,12 @@
struct snd_card *card;
for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
- read_lock(&snd_card_rwlock);
+ mutex_lock(&snd_card_mutex);
if ((card = snd_cards[idx]) != NULL) {
count++;
snd_iprintf(buffer, "%s\n", card->longname);
}
- read_unlock(&snd_card_rwlock);
+ mutex_unlock(&snd_card_mutex);
}
if (!count) {
snd_iprintf(buffer, "--- no soundcards ---\n");
@@ -575,11 +586,11 @@
struct snd_card *card;
for (idx = 0; idx < SNDRV_CARDS; idx++) {
- read_lock(&snd_card_rwlock);
+ mutex_lock(&snd_card_mutex);
if ((card = snd_cards[idx]) != NULL)
snd_iprintf(buffer, "%2i %s\n",
idx, card->module->name);
- read_unlock(&snd_card_rwlock);
+ mutex_unlock(&snd_card_mutex);
}
}
#endif