aboutsummaryrefslogtreecommitdiffstats
path: root/sound/core
diff options
context:
space:
mode:
authorTakashi Iwai <tiwai@suse.de>2012-10-30 11:08:25 +0100
committerTakashi Iwai <tiwai@suse.de>2012-10-30 11:08:25 +0100
commita5d00dc3a4b65ed38249f3225e453944c633747b (patch)
tree6249ca5a5f13059f42890525a9ea7133778f3891 /sound/core
parentALSA: hda - Add tracepoints to HD-audio controller driver (diff)
parentALSA: Avoid endless sleep after disconnect (diff)
downloadlinux-dev-a5d00dc3a4b65ed38249f3225e453944c633747b.tar.xz
linux-dev-a5d00dc3a4b65ed38249f3225e453944c633747b.zip
Merge branch 'for-linus' into for-next
... for migrating the core changes for USB-audio disconnection fixes
Diffstat (limited to 'sound/core')
-rw-r--r--sound/core/compress_offload.c9
-rw-r--r--sound/core/control.c5
-rw-r--r--sound/core/hwdep.c12
-rw-r--r--sound/core/init.c50
-rw-r--r--sound/core/oss/mixer_oss.c10
-rw-r--r--sound/core/oss/pcm_oss.c6
-rw-r--r--sound/core/pcm.c13
-rw-r--r--sound/core/pcm_native.c33
-rw-r--r--sound/core/rawmidi.c26
-rw-r--r--sound/core/sound.c11
-rw-r--r--sound/core/sound_oss.c10
11 files changed, 147 insertions, 38 deletions
diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c
index c40ae573346d..ad11dc994792 100644
--- a/sound/core/compress_offload.c
+++ b/sound/core/compress_offload.c
@@ -100,12 +100,15 @@ static int snd_compr_open(struct inode *inode, struct file *f)
if (dirn != compr->direction) {
pr_err("this device doesn't support this direction\n");
+ snd_card_unref(compr->card);
return -EINVAL;
}
data = kzalloc(sizeof(*data), GFP_KERNEL);
- if (!data)
+ if (!data) {
+ snd_card_unref(compr->card);
return -ENOMEM;
+ }
data->stream.ops = compr->ops;
data->stream.direction = dirn;
data->stream.private_data = compr->private_data;
@@ -113,6 +116,7 @@ static int snd_compr_open(struct inode *inode, struct file *f)
runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
if (!runtime) {
kfree(data);
+ snd_card_unref(compr->card);
return -ENOMEM;
}
runtime->state = SNDRV_PCM_STATE_OPEN;
@@ -126,7 +130,8 @@ static int snd_compr_open(struct inode *inode, struct file *f)
kfree(runtime);
kfree(data);
}
- return ret;
+ snd_card_unref(compr->card);
+ return 0;
}
static int snd_compr_free(struct inode *inode, struct file *f)
diff --git a/sound/core/control.c b/sound/core/control.c
index 7e86a5b9f3b5..8c7c2c9bba61 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -86,6 +86,7 @@ static int snd_ctl_open(struct inode *inode, struct file *file)
write_lock_irqsave(&card->ctl_files_rwlock, flags);
list_add_tail(&ctl->list, &card->ctl_files);
write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
+ snd_card_unref(card);
return 0;
__error:
@@ -93,6 +94,8 @@ static int snd_ctl_open(struct inode *inode, struct file *file)
__error2:
snd_card_file_remove(card, file);
__error1:
+ if (card)
+ snd_card_unref(card);
return err;
}
@@ -1434,6 +1437,8 @@ static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
spin_unlock_irq(&ctl->read_lock);
schedule();
remove_wait_queue(&ctl->change_sleep, &wait);
+ if (ctl->card->shutdown)
+ return -ENODEV;
if (signal_pending(current))
return -ERESTARTSYS;
spin_lock_irq(&ctl->read_lock);
diff --git a/sound/core/hwdep.c b/sound/core/hwdep.c
index 75ea16f35b1a..3f7f6628cf7b 100644
--- a/sound/core/hwdep.c
+++ b/sound/core/hwdep.c
@@ -100,8 +100,10 @@ static int snd_hwdep_open(struct inode *inode, struct file * file)
if (hw == NULL)
return -ENODEV;
- if (!try_module_get(hw->card->module))
+ if (!try_module_get(hw->card->module)) {
+ snd_card_unref(hw->card);
return -EFAULT;
+ }
init_waitqueue_entry(&wait, current);
add_wait_queue(&hw->open_wait, &wait);
@@ -129,6 +131,10 @@ static int snd_hwdep_open(struct inode *inode, struct file * file)
mutex_unlock(&hw->open_mutex);
schedule();
mutex_lock(&hw->open_mutex);
+ if (hw->card->shutdown) {
+ err = -ENODEV;
+ break;
+ }
if (signal_pending(current)) {
err = -ERESTARTSYS;
break;
@@ -148,6 +154,7 @@ static int snd_hwdep_open(struct inode *inode, struct file * file)
mutex_unlock(&hw->open_mutex);
if (err < 0)
module_put(hw->card->module);
+ snd_card_unref(hw->card);
return err;
}
@@ -459,12 +466,15 @@ static int snd_hwdep_dev_disconnect(struct snd_device *device)
mutex_unlock(&register_mutex);
return -EINVAL;
}
+ mutex_lock(&hwdep->open_mutex);
+ wake_up(&hwdep->open_wait);
#ifdef CONFIG_SND_OSSEMUL
if (hwdep->ossreg)
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_init(&hwdep->list);
+ mutex_unlock(&hwdep->open_mutex);
mutex_unlock(&register_mutex);
return 0;
}
diff --git a/sound/core/init.c b/sound/core/init.c
index d8ec849af128..7b012d15c2cf 100644
--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -213,6 +213,7 @@ int snd_card_create(int idx, const char *xid,
spin_lock_init(&card->files_lock);
INIT_LIST_HEAD(&card->files_list);
init_waitqueue_head(&card->shutdown_sleep);
+ atomic_set(&card->refcount, 0);
#ifdef CONFIG_PM
mutex_init(&card->power_lock);
init_waitqueue_head(&card->power_sleep);
@@ -446,21 +447,36 @@ static int snd_card_do_free(struct snd_card *card)
return 0;
}
+/**
+ * snd_card_unref - release the reference counter
+ * @card: the card instance
+ *
+ * Decrements the reference counter. When it reaches to zero, wake up
+ * the sleeper and call the destructor if needed.
+ */
+void snd_card_unref(struct snd_card *card)
+{
+ if (atomic_dec_and_test(&card->refcount)) {
+ wake_up(&card->shutdown_sleep);
+ if (card->free_on_last_close)
+ snd_card_do_free(card);
+ }
+}
+EXPORT_SYMBOL(snd_card_unref);
+
int snd_card_free_when_closed(struct snd_card *card)
{
- int free_now = 0;
- int ret = snd_card_disconnect(card);
- if (ret)
- return ret;
+ int ret;
- spin_lock(&card->files_lock);
- if (list_empty(&card->files_list))
- free_now = 1;
- else
- card->free_on_last_close = 1;
- spin_unlock(&card->files_lock);
+ atomic_inc(&card->refcount);
+ ret = snd_card_disconnect(card);
+ if (ret) {
+ atomic_dec(&card->refcount);
+ return ret;
+ }
- if (free_now)
+ card->free_on_last_close = 1;
+ if (atomic_dec_and_test(&card->refcount))
snd_card_do_free(card);
return 0;
}
@@ -474,7 +490,7 @@ int snd_card_free(struct snd_card *card)
return ret;
/* wait, until all devices are ready for the free operation */
- wait_event(card->shutdown_sleep, list_empty(&card->files_list));
+ wait_event(card->shutdown_sleep, !atomic_read(&card->refcount));
snd_card_do_free(card);
return 0;
}
@@ -886,6 +902,7 @@ int snd_card_file_add(struct snd_card *card, struct file *file)
return -ENODEV;
}
list_add(&mfile->list, &card->files_list);
+ atomic_inc(&card->refcount);
spin_unlock(&card->files_lock);
return 0;
}
@@ -908,7 +925,6 @@ EXPORT_SYMBOL(snd_card_file_add);
int snd_card_file_remove(struct snd_card *card, struct file *file)
{
struct snd_monitor_file *mfile, *found = NULL;
- int last_close = 0;
spin_lock(&card->files_lock);
list_for_each_entry(mfile, &card->files_list, list) {
@@ -923,19 +939,13 @@ int snd_card_file_remove(struct snd_card *card, struct file *file)
break;
}
}
- if (list_empty(&card->files_list))
- 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 (!found) {
snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file);
return -ENOENT;
}
kfree(found);
+ snd_card_unref(card);
return 0;
}
diff --git a/sound/core/oss/mixer_oss.c b/sound/core/oss/mixer_oss.c
index 29f6ded02555..a9a2e63c0222 100644
--- a/sound/core/oss/mixer_oss.c
+++ b/sound/core/oss/mixer_oss.c
@@ -52,14 +52,19 @@ static int snd_mixer_oss_open(struct inode *inode, struct file *file)
SNDRV_OSS_DEVICE_TYPE_MIXER);
if (card == NULL)
return -ENODEV;
- if (card->mixer_oss == NULL)
+ if (card->mixer_oss == NULL) {
+ snd_card_unref(card);
return -ENODEV;
+ }
err = snd_card_file_add(card, file);
- if (err < 0)
+ if (err < 0) {
+ snd_card_unref(card);
return err;
+ }
fmixer = kzalloc(sizeof(*fmixer), GFP_KERNEL);
if (fmixer == NULL) {
snd_card_file_remove(card, file);
+ snd_card_unref(card);
return -ENOMEM;
}
fmixer->card = card;
@@ -68,6 +73,7 @@ static int snd_mixer_oss_open(struct inode *inode, struct file *file)
if (!try_module_get(card->module)) {
kfree(fmixer);
snd_card_file_remove(card, file);
+ snd_card_unref(card);
return -EFAULT;
}
return 0;
diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c
index 08fde0060fd9..f337b66a020b 100644
--- a/sound/core/oss/pcm_oss.c
+++ b/sound/core/oss/pcm_oss.c
@@ -2441,6 +2441,10 @@ static int snd_pcm_oss_open(struct inode *inode, struct file *file)
mutex_unlock(&pcm->open_mutex);
schedule();
mutex_lock(&pcm->open_mutex);
+ if (pcm->card->shutdown) {
+ err = -ENODEV;
+ break;
+ }
if (signal_pending(current)) {
err = -ERESTARTSYS;
break;
@@ -2457,6 +2461,8 @@ static int snd_pcm_oss_open(struct inode *inode, struct file *file)
__error2:
snd_card_file_remove(pcm->card, file);
__error1:
+ if (pcm)
+ snd_card_unref(pcm->card);
return err;
}
diff --git a/sound/core/pcm.c b/sound/core/pcm.c
index f2991940b271..030102caeee9 100644
--- a/sound/core/pcm.c
+++ b/sound/core/pcm.c
@@ -1086,11 +1086,19 @@ static int snd_pcm_dev_disconnect(struct snd_device *device)
if (list_empty(&pcm->list))
goto unlock;
+ mutex_lock(&pcm->open_mutex);
+ wake_up(&pcm->open_wait);
list_del_init(&pcm->list);
for (cidx = 0; cidx < 2; cidx++)
- for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
- if (substream->runtime)
+ for (substream = pcm->streams[cidx].substream; substream; substream = substream->next) {
+ snd_pcm_stream_lock_irq(substream);
+ if (substream->runtime) {
substream->runtime->status->state = SNDRV_PCM_STATE_DISCONNECTED;
+ wake_up(&substream->runtime->sleep);
+ wake_up(&substream->runtime->tsleep);
+ }
+ snd_pcm_stream_unlock_irq(substream);
+ }
list_for_each_entry(notify, &snd_pcm_notify_list, list) {
notify->n_disconnect(pcm);
}
@@ -1110,6 +1118,7 @@ static int snd_pcm_dev_disconnect(struct snd_device *device)
pcm->streams[cidx].chmap_kctl = NULL;
}
}
+ mutex_unlock(&pcm->open_mutex);
unlock:
mutex_unlock(&register_mutex);
return 0;
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 7c800012fff9..b329ca58e63c 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -369,6 +369,14 @@ static int period_to_usecs(struct snd_pcm_runtime *runtime)
return usecs;
}
+static void snd_pcm_set_state(struct snd_pcm_substream *substream, int state)
+{
+ snd_pcm_stream_lock_irq(substream);
+ if (substream->runtime->status->state != SNDRV_PCM_STATE_DISCONNECTED)
+ substream->runtime->status->state = state;
+ snd_pcm_stream_unlock_irq(substream);
+}
+
static int snd_pcm_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params)
{
@@ -452,7 +460,7 @@ static int snd_pcm_hw_params(struct snd_pcm_substream *substream,
runtime->boundary *= 2;
snd_pcm_timer_resolution_change(substream);
- runtime->status->state = SNDRV_PCM_STATE_SETUP;
+ snd_pcm_set_state(substream, SNDRV_PCM_STATE_SETUP);
if (pm_qos_request_active(&substream->latency_pm_qos_req))
pm_qos_remove_request(&substream->latency_pm_qos_req);
@@ -464,7 +472,7 @@ static int snd_pcm_hw_params(struct snd_pcm_substream *substream,
/* hardware might be unusable from this time,
so we force application to retry to set
the correct hardware parameter settings */
- runtime->status->state = SNDRV_PCM_STATE_OPEN;
+ snd_pcm_set_state(substream, SNDRV_PCM_STATE_OPEN);
if (substream->ops->hw_free != NULL)
substream->ops->hw_free(substream);
return err;
@@ -512,7 +520,7 @@ static int snd_pcm_hw_free(struct snd_pcm_substream *substream)
return -EBADFD;
if (substream->ops->hw_free)
result = substream->ops->hw_free(substream);
- runtime->status->state = SNDRV_PCM_STATE_OPEN;
+ snd_pcm_set_state(substream, SNDRV_PCM_STATE_OPEN);
pm_qos_remove_request(&substream->latency_pm_qos_req);
return result;
}
@@ -1322,7 +1330,7 @@ static void snd_pcm_post_prepare(struct snd_pcm_substream *substream, int state)
{
struct snd_pcm_runtime *runtime = substream->runtime;
runtime->control->appl_ptr = runtime->status->hw_ptr;
- runtime->status->state = SNDRV_PCM_STATE_PREPARED;
+ snd_pcm_set_state(substream, SNDRV_PCM_STATE_PREPARED);
}
static struct action_ops snd_pcm_action_prepare = {
@@ -1512,6 +1520,10 @@ static int snd_pcm_drain(struct snd_pcm_substream *substream,
down_read(&snd_pcm_link_rwsem);
snd_pcm_stream_lock_irq(substream);
remove_wait_queue(&to_check->sleep, &wait);
+ if (card->shutdown) {
+ result = -ENODEV;
+ break;
+ }
if (tout == 0) {
if (substream->runtime->status->state == SNDRV_PCM_STATE_SUSPENDED)
result = -ESTRPIPE;
@@ -1636,6 +1648,7 @@ static int snd_pcm_link(struct snd_pcm_substream *substream, int fd)
write_unlock_irq(&snd_pcm_link_rwlock);
up_write(&snd_pcm_link_rwsem);
_nolock:
+ snd_card_unref(substream1->pcm->card);
fput_light(file, fput_needed);
if (res < 0)
kfree(group);
@@ -2110,7 +2123,9 @@ static int snd_pcm_playback_open(struct inode *inode, struct file *file)
return err;
pcm = snd_lookup_minor_data(iminor(inode),
SNDRV_DEVICE_TYPE_PCM_PLAYBACK);
- return snd_pcm_open(file, pcm, SNDRV_PCM_STREAM_PLAYBACK);
+ err = snd_pcm_open(file, pcm, SNDRV_PCM_STREAM_PLAYBACK);
+ snd_card_unref(pcm->card);
+ return err;
}
static int snd_pcm_capture_open(struct inode *inode, struct file *file)
@@ -2121,7 +2136,9 @@ static int snd_pcm_capture_open(struct inode *inode, struct file *file)
return err;
pcm = snd_lookup_minor_data(iminor(inode),
SNDRV_DEVICE_TYPE_PCM_CAPTURE);
- return snd_pcm_open(file, pcm, SNDRV_PCM_STREAM_CAPTURE);
+ err = snd_pcm_open(file, pcm, SNDRV_PCM_STREAM_CAPTURE);
+ snd_card_unref(pcm->card);
+ return err;
}
static int snd_pcm_open(struct file *file, struct snd_pcm *pcm, int stream)
@@ -2158,6 +2175,10 @@ static int snd_pcm_open(struct file *file, struct snd_pcm *pcm, int stream)
mutex_unlock(&pcm->open_mutex);
schedule();
mutex_lock(&pcm->open_mutex);
+ if (pcm->card->shutdown) {
+ err = -ENODEV;
+ break;
+ }
if (signal_pending(current)) {
err = -ERESTARTSYS;
break;
diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c
index ebf6e49ad3d4..1bb95aeea084 100644
--- a/sound/core/rawmidi.c
+++ b/sound/core/rawmidi.c
@@ -379,8 +379,10 @@ static int snd_rawmidi_open(struct inode *inode, struct file *file)
if (rmidi == NULL)
return -ENODEV;
- if (!try_module_get(rmidi->card->module))
+ if (!try_module_get(rmidi->card->module)) {
+ snd_card_unref(rmidi->card);
return -ENXIO;
+ }
mutex_lock(&rmidi->open_mutex);
card = rmidi->card;
@@ -422,6 +424,10 @@ static int snd_rawmidi_open(struct inode *inode, struct file *file)
mutex_unlock(&rmidi->open_mutex);
schedule();
mutex_lock(&rmidi->open_mutex);
+ if (rmidi->card->shutdown) {
+ err = -ENODEV;
+ break;
+ }
if (signal_pending(current)) {
err = -ERESTARTSYS;
break;
@@ -440,6 +446,7 @@ static int snd_rawmidi_open(struct inode *inode, struct file *file)
#endif
file->private_data = rawmidi_file;
mutex_unlock(&rmidi->open_mutex);
+ snd_card_unref(rmidi->card);
return 0;
__error:
@@ -447,6 +454,7 @@ static int snd_rawmidi_open(struct inode *inode, struct file *file)
__error_card:
mutex_unlock(&rmidi->open_mutex);
module_put(rmidi->card->module);
+ snd_card_unref(rmidi->card);
return err;
}
@@ -991,6 +999,8 @@ static ssize_t snd_rawmidi_read(struct file *file, char __user *buf, size_t coun
spin_unlock_irq(&runtime->lock);
schedule();
remove_wait_queue(&runtime->sleep, &wait);
+ if (rfile->rmidi->card->shutdown)
+ return -ENODEV;
if (signal_pending(current))
return result > 0 ? result : -ERESTARTSYS;
if (!runtime->avail)
@@ -1234,6 +1244,8 @@ static ssize_t snd_rawmidi_write(struct file *file, const char __user *buf,
spin_unlock_irq(&runtime->lock);
timeout = schedule_timeout(30 * HZ);
remove_wait_queue(&runtime->sleep, &wait);
+ if (rfile->rmidi->card->shutdown)
+ return -ENODEV;
if (signal_pending(current))
return result > 0 ? result : -ERESTARTSYS;
if (!runtime->avail && !timeout)
@@ -1609,9 +1621,20 @@ static int snd_rawmidi_dev_register(struct snd_device *device)
static int snd_rawmidi_dev_disconnect(struct snd_device *device)
{
struct snd_rawmidi *rmidi = device->device_data;
+ int dir;
mutex_lock(&register_mutex);
+ mutex_lock(&rmidi->open_mutex);
+ wake_up(&rmidi->open_wait);
list_del_init(&rmidi->list);
+ for (dir = 0; dir < 2; dir++) {
+ struct snd_rawmidi_substream *s;
+ list_for_each_entry(s, &rmidi->streams[dir].substreams, list) {
+ if (s->runtime)
+ wake_up(&s->runtime->sleep);
+ }
+ }
+
#ifdef CONFIG_SND_OSSEMUL
if (rmidi->ossreg) {
if ((int)rmidi->device == midi_map[rmidi->card->number]) {
@@ -1626,6 +1649,7 @@ static int snd_rawmidi_dev_disconnect(struct snd_device *device)
}
#endif /* CONFIG_SND_OSSEMUL */
snd_unregister_device(SNDRV_DEVICE_TYPE_RAWMIDI, rmidi->card, rmidi->device);
+ mutex_unlock(&rmidi->open_mutex);
mutex_unlock(&register_mutex);
return 0;
}
diff --git a/sound/core/sound.c b/sound/core/sound.c
index 643976000ce8..89780c323f19 100644
--- a/sound/core/sound.c
+++ b/sound/core/sound.c
@@ -98,6 +98,10 @@ static void snd_request_other(int minor)
*
* Checks that a minor device with the specified type is registered, and returns
* its user data pointer.
+ *
+ * This function increments the reference counter of the card instance
+ * if an associated instance with the given minor number and type is found.
+ * The caller must call snd_card_unref() appropriately later.
*/
void *snd_lookup_minor_data(unsigned int minor, int type)
{
@@ -108,9 +112,11 @@ void *snd_lookup_minor_data(unsigned int minor, int type)
return NULL;
mutex_lock(&sound_mutex);
mreg = snd_minors[minor];
- if (mreg && mreg->type == type)
+ if (mreg && mreg->type == type) {
private_data = mreg->private_data;
- else
+ if (mreg->card_ptr)
+ atomic_inc(&mreg->card_ptr->refcount);
+ } else
private_data = NULL;
mutex_unlock(&sound_mutex);
return private_data;
@@ -275,6 +281,7 @@ int snd_register_device_for_dev(int type, struct snd_card *card, int dev,
preg->device = dev;
preg->f_ops = f_ops;
preg->private_data = private_data;
+ preg->card_ptr = card;
mutex_lock(&sound_mutex);
#ifdef CONFIG_SND_DYNAMIC_MINORS
minor = snd_find_free_minor(type);
diff --git a/sound/core/sound_oss.c b/sound/core/sound_oss.c
index e9528333e36d..e1d79ee35906 100644
--- a/sound/core/sound_oss.c
+++ b/sound/core/sound_oss.c
@@ -40,6 +40,9 @@
static struct snd_minor *snd_oss_minors[SNDRV_OSS_MINORS];
static DEFINE_MUTEX(sound_oss_mutex);
+/* NOTE: This function increments the refcount of the associated card like
+ * snd_lookup_minor_data(); the caller must call snd_card_unref() appropriately
+ */
void *snd_lookup_oss_minor_data(unsigned int minor, int type)
{
struct snd_minor *mreg;
@@ -49,9 +52,11 @@ void *snd_lookup_oss_minor_data(unsigned int minor, int type)
return NULL;
mutex_lock(&sound_oss_mutex);
mreg = snd_oss_minors[minor];
- if (mreg && mreg->type == type)
+ if (mreg && mreg->type == type) {
private_data = mreg->private_data;
- else
+ if (mreg->card_ptr)
+ atomic_inc(&mreg->card_ptr->refcount);
+ } else
private_data = NULL;
mutex_unlock(&sound_oss_mutex);
return private_data;
@@ -123,6 +128,7 @@ int snd_register_oss_device(int type, struct snd_card *card, int dev,
preg->device = dev;
preg->f_ops = f_ops;
preg->private_data = private_data;
+ preg->card_ptr = card;
mutex_lock(&sound_oss_mutex);
snd_oss_minors[minor] = preg;
minor_unit = SNDRV_MINOR_OSS_DEVICE(minor);