[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>

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);

include/sound/timer.h

@@ -129,7 +129,6 @@ void snd_timer_notify(struct snd_timer *timer, int event, struct timespec *tstam
 int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer);
 int snd_timer_global_free(struct snd_timer *timer);
 int snd_timer_global_register(struct snd_timer *timer);
-int snd_timer_global_unregister(struct snd_timer *timer);
 
 int snd_timer_open(struct snd_timer_instance **ti, char *owner, struct snd_timer_id *tid, unsigned int slave_id);
 int snd_timer_close(struct snd_timer_instance *timeri);

sound/core/control.c

@@ -1375,6 +1375,11 @@ static int snd_ctl_dev_disconnect(struct snd_device *device)
 	struct snd_card *card = device->device_data;
 	struct list_head *flist;
 	struct snd_ctl_file *ctl;
+	int err, cardnum;
+
+	snd_assert(card != NULL, return -ENXIO);
+	cardnum = card->number;
+	snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
 
 	down_read(&card->controls_rwsem);
 	list_for_each(flist, &card->ctl_files) {
@@ -1383,6 +1388,10 @@ static int snd_ctl_dev_disconnect(struct snd_device *device)
 		kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
 	}
 	up_read(&card->controls_rwsem);
+
+	if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
+					 card, -1)) < 0)
+		return err;
 	return 0;
 }
 
@@ -1403,23 +1412,6 @@ static int snd_ctl_dev_free(struct snd_device *device)
 	return 0;
 }
 
-/*
- * de-registration of the control device
- */
-static int snd_ctl_dev_unregister(struct snd_device *device)
-{
-	struct snd_card *card = device->device_data;
-	int err, cardnum;
-
-	snd_assert(card != NULL, return -ENXIO);
-	cardnum = card->number;
-	snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
-	if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
-					 card, -1)) < 0)
-		return err;
-	return snd_ctl_dev_free(device);
-}
-
 /*
  * create control core:
  * called from init.c
@@ -1430,7 +1422,6 @@ int snd_ctl_create(struct snd_card *card)
 		.dev_free = snd_ctl_dev_free,
 		.dev_register =	snd_ctl_dev_register,
 		.dev_disconnect = snd_ctl_dev_disconnect,
-		.dev_unregister = snd_ctl_dev_unregister
 	};
 
 	snd_assert(card != NULL, return -ENXIO);

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;

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

sound/core/init.c

@@ -327,22 +327,10 @@ EXPORT_SYMBOL(snd_card_disconnect);
  *  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 @@ int snd_card_free(struct snd_card *card)
 		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 @@ EXPORT_SYMBOL(snd_card_file_add);
 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 @@ int snd_card_file_remove(struct snd_card *card, struct file *file)
 		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;

sound/core/oss/mixer_oss.c

@@ -1310,21 +1310,19 @@ static int snd_mixer_oss_notify_handler(struct snd_card *card, int cmd)
 		card->mixer_oss = mixer;
 		snd_mixer_oss_build(mixer);
 		snd_mixer_oss_proc_init(mixer);
-	} else if (cmd == SND_MIXER_OSS_NOTIFY_DISCONNECT) {
-		mixer = card->mixer_oss;
-		if (mixer == NULL || !mixer->oss_dev_alloc)
-			return 0;
-		snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_MIXER, mixer->card, 0);
-		mixer->oss_dev_alloc = 0;
-	} else {		/* free */
+	} else {
 		mixer = card->mixer_oss;
 		if (mixer == NULL)
 			return 0;
+		if (mixer->oss_dev_alloc) {
 #ifdef SNDRV_OSS_INFO_DEV_MIXERS
-		snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_MIXERS, mixer->card->number);
+			snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_MIXERS, mixer->card->number);
 #endif
-		if (mixer->oss_dev_alloc)
 			snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_MIXER, mixer->card, 0);
+			mixer->oss_dev_alloc = 0;
+		}
+		if (cmd == SND_MIXER_OSS_NOTIFY_DISCONNECT)
+			return 0;
 		snd_mixer_oss_proc_done(mixer);
 		return snd_mixer_oss_free1(mixer);
 	}

sound/core/oss/pcm_oss.c

@@ -2929,25 +2929,23 @@ static int snd_pcm_oss_disconnect_minor(struct snd_pcm *pcm)
 			snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_PCM,
 						  pcm->card, 1);
 		}
-	}
-	return 0;
-}
-
-static int snd_pcm_oss_unregister_minor(struct snd_pcm *pcm)
-{
-	snd_pcm_oss_disconnect_minor(pcm);
-	if (pcm->oss.reg) {
 		if (dsp_map[pcm->card->number] == (int)pcm->device) {
 #ifdef SNDRV_OSS_INFO_DEV_AUDIO
 			snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_AUDIO, pcm->card->number);
 #endif
 		}
 		pcm->oss.reg = 0;
-		snd_pcm_oss_proc_done(pcm);
 	}
 	return 0;
 }
 
+static int snd_pcm_oss_unregister_minor(struct snd_pcm *pcm)
+{
+	snd_pcm_oss_disconnect_minor(pcm);
+	snd_pcm_oss_proc_done(pcm);
+	return 0;
+}
+
 static struct snd_pcm_notify snd_pcm_oss_notify =
 {
 	.n_register =	snd_pcm_oss_register_minor,

sound/core/pcm.c

@@ -42,7 +42,6 @@ static int snd_pcm_free(struct snd_pcm *pcm);
 static int snd_pcm_dev_free(struct snd_device *device);
 static int snd_pcm_dev_register(struct snd_device *device);
 static int snd_pcm_dev_disconnect(struct snd_device *device);
-static int snd_pcm_dev_unregister(struct snd_device *device);
 
 static struct snd_pcm *snd_pcm_search(struct snd_card *card, int device)
 {
@@ -680,7 +679,6 @@ int snd_pcm_new(struct snd_card *card, char *id, int device,
 		.dev_free = snd_pcm_dev_free,
 		.dev_register =	snd_pcm_dev_register,
 		.dev_disconnect = snd_pcm_dev_disconnect,
-		.dev_unregister = snd_pcm_dev_unregister
 	};
 
 	snd_assert(rpcm != NULL, return -EINVAL);
@@ -724,6 +722,7 @@ static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
 	substream = pstr->substream;
 	while (substream) {
 		substream_next = substream->next;
+		snd_pcm_timer_done(substream);
 		snd_pcm_substream_proc_done(substream);
 		kfree(substream);
 		substream = substream_next;
@@ -740,7 +739,12 @@ static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
 
 static int snd_pcm_free(struct snd_pcm *pcm)
 {
+	struct snd_pcm_notify *notify;
+
 	snd_assert(pcm != NULL, return -ENXIO);
+	list_for_each_entry(notify, &snd_pcm_notify_list, list) {
+		notify->n_unregister(pcm);
+	}
 	if (pcm->private_free)
 		pcm->private_free(pcm);
 	snd_pcm_lib_preallocate_free_for_all(pcm);
@@ -955,35 +959,22 @@ static int snd_pcm_dev_register(struct snd_device *device)
 static int snd_pcm_dev_disconnect(struct snd_device *device)
 {
 	struct snd_pcm *pcm = device->device_data;
-	struct list_head *list;
+	struct snd_pcm_notify *notify;
 	struct snd_pcm_substream *substream;
-	int cidx;
+	int cidx, devtype;
 
 	mutex_lock(&register_mutex);
+	if (list_empty(&pcm->list))
+		goto unlock;
+
 	list_del_init(&pcm->list);
 	for (cidx = 0; cidx < 2; cidx++)
 		for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
 			if (substream->runtime)
 				substream->runtime->status->state = SNDRV_PCM_STATE_DISCONNECTED;
-	list_for_each(list, &snd_pcm_notify_list) {
-		struct snd_pcm_notify *notify;
-		notify = list_entry(list, struct snd_pcm_notify, list);
+	list_for_each_entry(notify, &snd_pcm_notify_list, list) {
 		notify->n_disconnect(pcm);
 	}
-	mutex_unlock(&register_mutex);
-	return 0;
-}
-
-static int snd_pcm_dev_unregister(struct snd_device *device)
-{
-	int cidx, devtype;
-	struct snd_pcm_substream *substream;
-	struct list_head *list;
-	struct snd_pcm *pcm = device->device_data;
-
-	snd_assert(pcm != NULL, return -ENXIO);
-	mutex_lock(&register_mutex);
-	list_del(&pcm->list);
 	for (cidx = 0; cidx < 2; cidx++) {
 		devtype = -1;
 		switch (cidx) {
@@ -995,23 +986,20 @@ static int snd_pcm_dev_unregister(struct snd_device *device)
 			break;
 		}
 		snd_unregister_device(devtype, pcm->card, pcm->device);
-		for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
-			snd_pcm_timer_done(substream);
-	}
-	list_for_each(list, &snd_pcm_notify_list) {
-		struct snd_pcm_notify *notify;
-		notify = list_entry(list, struct snd_pcm_notify, list);
-		notify->n_unregister(pcm);
 	}
+ unlock:
 	mutex_unlock(&register_mutex);
-	return snd_pcm_free(pcm);
+	return 0;
 }
 
 int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
 {
 	struct list_head *p;
 
-	snd_assert(notify != NULL && notify->n_register != NULL && notify->n_unregister != NULL, return -EINVAL);
+	snd_assert(notify != NULL &&
+		   notify->n_register != NULL &&
+		   notify->n_unregister != NULL &&
+		   notify->n_disconnect, return -EINVAL);
 	mutex_lock(&register_mutex);
 	if (nfree) {
 		list_del(&notify->list);

sound/core/rawmidi.c

@@ -55,7 +55,6 @@ static int snd_rawmidi_free(struct snd_rawmidi *rawmidi);
 static int snd_rawmidi_dev_free(struct snd_device *device);
 static int snd_rawmidi_dev_register(struct snd_device *device);
 static int snd_rawmidi_dev_disconnect(struct snd_device *device);
-static int snd_rawmidi_dev_unregister(struct snd_device *device);
 
 static LIST_HEAD(snd_rawmidi_devices);
 static DEFINE_MUTEX(register_mutex);
@@ -1426,7 +1425,6 @@ int snd_rawmidi_new(struct snd_card *card, char *id, int device,
 		.dev_free = snd_rawmidi_dev_free,
 		.dev_register = snd_rawmidi_dev_register,
 		.dev_disconnect = snd_rawmidi_dev_disconnect,
-		.dev_unregister = snd_rawmidi_dev_unregister
 	};
 
 	snd_assert(rrawmidi != NULL, return -EINVAL);
@@ -1479,6 +1477,14 @@ static void snd_rawmidi_free_substreams(struct snd_rawmidi_str *stream)
 static int snd_rawmidi_free(struct snd_rawmidi *rmidi)
 {
 	snd_assert(rmidi != NULL, return -ENXIO);	
+
+	snd_info_free_entry(rmidi->proc_entry);
+	rmidi->proc_entry = NULL;
+	mutex_lock(&register_mutex);
+	if (rmidi->ops && rmidi->ops->dev_unregister)
+		rmidi->ops->dev_unregister(rmidi);
+	mutex_unlock(&register_mutex);
+
 	snd_rawmidi_free_substreams(&rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT]);
 	snd_rawmidi_free_substreams(&rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT]);
 	if (rmidi->private_free)
@@ -1587,21 +1593,6 @@ static int snd_rawmidi_dev_disconnect(struct snd_device *device)
 
 	mutex_lock(&register_mutex);
 	list_del_init(&rmidi->list);
-	mutex_unlock(&register_mutex);
-	return 0;
-}
-
-static int snd_rawmidi_dev_unregister(struct snd_device *device)
-{
-	struct snd_rawmidi *rmidi = device->device_data;
-
-	snd_assert(rmidi != NULL, return -ENXIO);
-	mutex_lock(&register_mutex);
-	list_del(&rmidi->list);
-	if (rmidi->proc_entry) {
-		snd_info_free_entry(rmidi->proc_entry);
-		rmidi->proc_entry = NULL;
-	}
 #ifdef CONFIG_SND_OSSEMUL
 	if (rmidi->ossreg) {
 		if ((int)rmidi->device == midi_map[rmidi->card->number]) {
@@ -1615,17 +1606,9 @@ static int snd_rawmidi_dev_unregister(struct snd_device *device)
 		rmidi->ossreg = 0;
 	}
 #endif /* CONFIG_SND_OSSEMUL */
-	if (rmidi->ops && rmidi->ops->dev_unregister)
-		rmidi->ops->dev_unregister(rmidi);
 	snd_unregister_device(SNDRV_DEVICE_TYPE_RAWMIDI, rmidi->card, rmidi->device);
 	mutex_unlock(&register_mutex);
-#if defined(CONFIG_SND_SEQUENCER) || (defined(MODULE) && defined(CONFIG_SND_SEQUENCER_MODULE))
-	if (rmidi->seq_dev) {
-		snd_device_free(rmidi->card, rmidi->seq_dev);
-		rmidi->seq_dev = NULL;
-	}
-#endif
-	return snd_rawmidi_free(rmidi);
+	return 0;
 }
 
 /**

sound/core/rtctimer.c

@@ -156,7 +156,7 @@ static int __init rtctimer_init(void)
 static void __exit rtctimer_exit(void)
 {
 	if (rtctimer) {
-		snd_timer_global_unregister(rtctimer);
+		snd_timer_global_free(rtctimer);
 		rtctimer = NULL;
 	}
 }

sound/core/seq/seq_device.c

@@ -90,7 +90,6 @@ static int snd_seq_device_free(struct snd_seq_device *dev);
 static int snd_seq_device_dev_free(struct snd_device *device);
 static int snd_seq_device_dev_register(struct snd_device *device);
 static int snd_seq_device_dev_disconnect(struct snd_device *device);
-static int snd_seq_device_dev_unregister(struct snd_device *device);
 
 static int init_device(struct snd_seq_device *dev, struct ops_list *ops);
 static int free_device(struct snd_seq_device *dev, struct ops_list *ops);
@@ -189,7 +188,6 @@ int snd_seq_device_new(struct snd_card *card, int device, char *id, int argsize,
 		.dev_free = snd_seq_device_dev_free,
 		.dev_register = snd_seq_device_dev_register,
 		.dev_disconnect = snd_seq_device_dev_disconnect,
-		.dev_unregister = snd_seq_device_dev_unregister
 	};
 
 	if (result)
@@ -308,15 +306,6 @@ static int snd_seq_device_dev_disconnect(struct snd_device *device)
 	return 0;
 }
 
-/*
- * unregister the existing device
- */
-static int snd_seq_device_dev_unregister(struct snd_device *device)
-{
-	struct snd_seq_device *dev = device->device_data;
-	return snd_seq_device_free(dev);
-}
-
 /*
  * register device driver
  * id = driver id

sound/core/timer.c

@@ -88,7 +88,7 @@ static DEFINE_MUTEX(register_mutex);
 static int snd_timer_free(struct snd_timer *timer);
 static int snd_timer_dev_free(struct snd_device *device);
 static int snd_timer_dev_register(struct snd_device *device);
-static int snd_timer_dev_unregister(struct snd_device *device);
+static int snd_timer_dev_disconnect(struct snd_device *device);
 
 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left);
 
@@ -773,7 +773,7 @@ int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
 	static struct snd_device_ops ops = {
 		.dev_free = snd_timer_dev_free,
 		.dev_register = snd_timer_dev_register,
-		.dev_unregister = snd_timer_dev_unregister
+		.dev_disconnect = snd_timer_dev_disconnect,
 	};
 
 	snd_assert(tid != NULL, return -EINVAL);
@@ -813,6 +813,21 @@ int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
 static int snd_timer_free(struct snd_timer *timer)
 {
 	snd_assert(timer != NULL, return -ENXIO);
+
+	mutex_lock(&register_mutex);
+	if (! list_empty(&timer->open_list_head)) {
+		struct list_head *p, *n;
+		struct snd_timer_instance *ti;
+		snd_printk(KERN_WARNING "timer %p is busy?\n", timer);
+		list_for_each_safe(p, n, &timer->open_list_head) {
+			list_del_init(p);
+			ti = list_entry(p, struct snd_timer_instance, open_list);
+			ti->timer = NULL;
+		}
+	}
+	list_del(&timer->device_list);
+	mutex_unlock(&register_mutex);
+
 	if (timer->private_free)
 		timer->private_free(timer);
 	kfree(timer);
@@ -867,30 +882,13 @@ static int snd_timer_dev_register(struct snd_device *dev)
 	return 0;
 }
 
-static int snd_timer_unregister(struct snd_timer *timer)
+static int snd_timer_dev_disconnect(struct snd_device *device)
 {
-	struct list_head *p, *n;
-	struct snd_timer_instance *ti;
-
-	snd_assert(timer != NULL, return -ENXIO);
+	struct snd_timer *timer = device->device_data;
 	mutex_lock(&register_mutex);
-	if (! list_empty(&timer->open_list_head)) {
-		snd_printk(KERN_WARNING "timer 0x%lx is busy?\n", (long)timer);
-		list_for_each_safe(p, n, &timer->open_list_head) {
-			list_del_init(p);
-			ti = list_entry(p, struct snd_timer_instance, open_list);
-			ti->timer = NULL;
-		}
-	}
-	list_del(&timer->device_list);
+	list_del_init(&timer->device_list);
 	mutex_unlock(&register_mutex);
-	return snd_timer_free(timer);
-}
-
-static int snd_timer_dev_unregister(struct snd_device *device)
-{
-	struct snd_timer *timer = device->device_data;
-	return snd_timer_unregister(timer);
+	return 0;
 }
 
 void snd_timer_notify(struct snd_timer *timer, int event, struct timespec *tstamp)
@@ -955,11 +953,6 @@ int snd_timer_global_register(struct snd_timer *timer)
 	return snd_timer_dev_register(&dev);
 }
 
-int snd_timer_global_unregister(struct snd_timer *timer)
-{
-	return snd_timer_unregister(timer);
-}
-
 /*
  *  System timer
  */
@@ -1982,7 +1975,7 @@ static void __exit alsa_timer_exit(void)
 	/* unregister the system timer */
 	list_for_each_safe(p, n, &snd_timer_list) {
 		struct snd_timer *timer = list_entry(p, struct snd_timer, device_list);
-		snd_timer_unregister(timer);
+		snd_timer_free(timer);
 	}
 	snd_timer_proc_done();
 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
@@ -2005,5 +1998,4 @@ EXPORT_SYMBOL(snd_timer_notify);
 EXPORT_SYMBOL(snd_timer_global_new);
 EXPORT_SYMBOL(snd_timer_global_free);
 EXPORT_SYMBOL(snd_timer_global_register);
-EXPORT_SYMBOL(snd_timer_global_unregister);
 EXPORT_SYMBOL(snd_timer_interrupt);

sound/pci/ac97/ac97_codec.c

@@ -1817,13 +1817,13 @@ static int snd_ac97_dev_register(struct snd_device *device)
 	return 0;
 }
 
-/* unregister ac97 codec */
-static int snd_ac97_dev_unregister(struct snd_device *device)
+/* disconnect ac97 codec */
+static int snd_ac97_dev_disconnect(struct snd_device *device)
 {
 	struct snd_ac97 *ac97 = device->device_data;
 	if (ac97->dev.bus)
 		device_unregister(&ac97->dev);
-	return snd_ac97_free(ac97);
+	return 0;
 }
 
 /* build_ops to do nothing */
@@ -1860,7 +1860,7 @@ int snd_ac97_mixer(struct snd_ac97_bus *bus, struct snd_ac97_template *template,
 	static struct snd_device_ops ops = {
 		.dev_free =	snd_ac97_dev_free,
 		.dev_register =	snd_ac97_dev_register,
-		.dev_unregister =	snd_ac97_dev_unregister,
+		.dev_disconnect =	snd_ac97_dev_disconnect,
 	};
 
 	snd_assert(rac97 != NULL, return -EINVAL);

sound/usb/usbaudio.c

@@ -3499,7 +3499,7 @@ static void snd_usb_audio_disconnect(struct usb_device *dev, void *ptr)
 		}
 		usb_chip[chip->index] = NULL;
 		mutex_unlock(&register_mutex);
-		snd_card_free(card);
+		snd_card_free_when_closed(card);
 	} else {
 		mutex_unlock(&register_mutex);
 	}