[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>

1 files changed, 2 insertions, 1 deletions

diff --git a/include/sound/core.h b/include/sound/core.h
index bab3ff457e40..cf4001cf6248 100644
--- a/include/sound/core.h
+++ b/include/sound/core.h
@@ -71,7 +71,6 @@ struct snd_device_ops {
         int (*dev_free)(struct snd_device *dev);
         int (*dev_register)(struct snd_device *dev);
         int (*dev_disconnect)(struct snd_device *dev);
-        int (*dev_unregister)(struct snd_device *dev);
 };
 
 struct snd_device {
@@ -131,6 +130,7 @@ struct snd_card {
                                                                 state */
         spinlock_t files_lock;          /* lock the files for this card */
         int shutdown;                   /* this card is going down */
+        int free_on_last_close;         /* free in context of file_release */
         wait_queue_head_t shutdown_sleep;
         struct work_struct free_workq;  /* for free in workqueue */
         struct device *dev;
@@ -244,6 +244,7 @@ struct snd_card *snd_card_new(int idx, const char *id,
                          struct module *module, int extra_size);
 int snd_card_disconnect(struct snd_card *card);
 int snd_card_free(struct snd_card *card);
+int snd_card_free_when_closed(struct snd_card *card);
 int snd_card_free_in_thread(struct snd_card *card);
 int snd_card_register(struct snd_card *card);
 int snd_card_info_init(void);