[ALSA] Unregister device files at disconnection
Orignally proposed by Sam Revitch <sam.revitch@gmail.com>.
Unregister device files at disconnection to avoid the futher accesses.
Also, the dev_unregister callback is removed and replaced with the
combination of disconnect + free.
A new function snd_card_free_when_closed() is introduced, which is
used in USB disconnect callback.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
diff --git a/sound/core/init.c b/sound/core/init.c
index 1ecb029..5850d99 100644
--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -327,22 +327,10 @@
* Returns zero. Frees all associated devices and frees the control
* interface associated to given soundcard.
*/
-int snd_card_free(struct snd_card *card)
+static int snd_card_do_free(struct snd_card *card)
{
struct snd_shutdown_f_ops *s_f_ops;
- if (card == NULL)
- return -EINVAL;
- mutex_lock(&snd_card_mutex);
- snd_cards[card->number] = NULL;
- mutex_unlock(&snd_card_mutex);
-
-#ifdef CONFIG_PM
- wake_up(&card->power_sleep);
-#endif
- /* wait, until all devices are ready for the free operation */
- wait_event(card->shutdown_sleep, card->files == NULL);
-
#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
if (snd_mixer_oss_notify_callback)
snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
@@ -371,10 +359,55 @@
card->s_f_ops = s_f_ops->next;
kfree(s_f_ops);
}
+ kfree(card);
+ return 0;
+}
+
+static int snd_card_free_prepare(struct snd_card *card)
+{
+ if (card == NULL)
+ return -EINVAL;
+ (void) snd_card_disconnect(card);
mutex_lock(&snd_card_mutex);
+ snd_cards[card->number] = NULL;
snd_cards_lock &= ~(1 << card->number);
mutex_unlock(&snd_card_mutex);
- kfree(card);
+#ifdef CONFIG_PM
+ wake_up(&card->power_sleep);
+#endif
+ return 0;
+}
+
+int snd_card_free_when_closed(struct snd_card *card)
+{
+ int free_now = 0;
+ int ret = snd_card_free_prepare(card);
+ if (ret)
+ return ret;
+
+ spin_lock(&card->files_lock);
+ if (card->files == NULL)
+ free_now = 1;
+ else
+ card->free_on_last_close = 1;
+ spin_unlock(&card->files_lock);
+
+ if (free_now)
+ snd_card_do_free(card);
+ return 0;
+}
+
+EXPORT_SYMBOL(snd_card_free_when_closed);
+
+int snd_card_free(struct snd_card *card)
+{
+ int ret = snd_card_free_prepare(card);
+ if (ret)
+ return ret;
+
+ /* wait, until all devices are ready for the free operation */
+ wait_event(card->shutdown_sleep, card->files == NULL);
+ snd_card_do_free(card);
return 0;
}
@@ -718,6 +751,7 @@
int snd_card_file_remove(struct snd_card *card, struct file *file)
{
struct snd_monitor_file *mfile, *pfile = NULL;
+ int last_close = 0;
spin_lock(&card->files_lock);
mfile = card->files;
@@ -732,9 +766,14 @@
pfile = mfile;
mfile = mfile->next;
}
- spin_unlock(&card->files_lock);
if (card->files == NULL)
+ last_close = 1;
+ spin_unlock(&card->files_lock);
+ if (last_close) {
wake_up(&card->shutdown_sleep);
+ if (card->free_on_last_close)
+ snd_card_do_free(card);
+ }
if (!mfile) {
snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file);
return -ENOENT;