[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, 5 insertions, 5 deletions

diff --git a/sound/core/hwdep.c b/sound/core/hwdep.c
index cbd8a63282b6..9aa9d94891f0 100644
--- a/sound/core/hwdep.c
+++ b/sound/core/hwdep.c
@@ -42,7 +42,7 @@ static DEFINE_MUTEX(register_mutex);
 static int snd_hwdep_free(struct snd_hwdep *hwdep);
 static int snd_hwdep_dev_free(struct snd_device *device);
 static int snd_hwdep_dev_register(struct snd_device *device);
-static int snd_hwdep_dev_unregister(struct snd_device *device);
+static int snd_hwdep_dev_disconnect(struct snd_device *device);
 
 
 static struct snd_hwdep *snd_hwdep_search(struct snd_card *card, int device)
@@ -353,7 +353,7 @@ int snd_hwdep_new(struct snd_card *card, char *id, int device,
         static struct snd_device_ops ops = {
                 .dev_free = snd_hwdep_dev_free,
                 .dev_register = snd_hwdep_dev_register,
-                .dev_unregister = snd_hwdep_dev_unregister
+                .dev_disconnect = snd_hwdep_dev_disconnect,
         };
 
         snd_assert(rhwdep != NULL, return -EINVAL);
@@ -439,7 +439,7 @@ static int snd_hwdep_dev_register(struct snd_device *device)
         return 0;
 }
 
-static int snd_hwdep_dev_unregister(struct snd_device *device)
+static int snd_hwdep_dev_disconnect(struct snd_device *device)
 {
         struct snd_hwdep *hwdep = device->device_data;
 
@@ -454,9 +454,9 @@ static int snd_hwdep_dev_unregister(struct snd_device *device)
                 snd_unregister_oss_device(hwdep->oss_type, hwdep->card, hwdep->device);
 #endif
         snd_unregister_device(SNDRV_DEVICE_TYPE_HWDEP, hwdep->card, hwdep->device);
-        list_del(&hwdep->list);
+        list_del_init(&hwdep->list);
         mutex_unlock(&register_mutex);
-        return snd_hwdep_free(hwdep);
+        return 0;
 }
 
 #ifdef CONFIG_PROC_FS