[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, 9 insertions, 11 deletions

diff --git a/sound/core/device.c b/sound/core/device.c
index 6ce4da4a108..ccb25816ac9 100644
--- a/sound/core/device.c
+++ b/sound/core/device.c
@@ -71,7 +71,7 @@ EXPORT_SYMBOL(snd_device_new);
  * @device_data: the data pointer to release
  *
  * Removes the device from the list on the card and invokes the
- * callback, dev_unregister or dev_free, corresponding to the state.
+ * callbacks, dev_disconnect and dev_free, corresponding to the state.
  * Then release the device.
  *
  * Returns zero if successful, or a negative error code on failure or if the
@@ -90,16 +90,14 @@ int snd_device_free(struct snd_card *card, void *device_data)
 			continue;
 		/* unlink */
 		list_del(&dev->list);
-		if ((dev->state == SNDRV_DEV_REGISTERED ||
-		     dev->state == SNDRV_DEV_DISCONNECTED) &&
-		    dev->ops->dev_unregister) {
-			if (dev->ops->dev_unregister(dev))
-				snd_printk(KERN_ERR "device unregister failure\n");
-		} else {
-			if (dev->ops->dev_free) {
-				if (dev->ops->dev_free(dev))
-					snd_printk(KERN_ERR "device free failure\n");
-			}
+		if (dev->state == SNDRV_DEV_REGISTERED &&
+		    dev->ops->dev_disconnect)
+			if (dev->ops->dev_disconnect(dev))
+				snd_printk(KERN_ERR
+					   "device disconnect failure\n");
+		if (dev->ops->dev_free) {
+			if (dev->ops->dev_free(dev))
+				snd_printk(KERN_ERR "device free failure\n");
 		}
 		kfree(dev);
 		return 0;