[ 36/57] ALSA: Avoid endless sleep after disconnect

From: Greg Kroah-Hartman
Date: Wed Nov 14 2012 - 23:12:50 EST


3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Takashi Iwai <tiwai@xxxxxxx>

commit 0914f7961babbf28aaa2f19b453951fb4841c03f upstream.

When disconnect callback is called, each component should wake up
sleepers and check card->shutdown flag for avoiding the endless sleep
blocking the proper resource release.

Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
sound/core/control.c | 2 ++
sound/core/hwdep.c | 7 +++++++
sound/core/oss/pcm_oss.c | 4 ++++
sound/core/pcm.c | 6 +++++-
sound/core/pcm_native.c | 8 ++++++++
sound/core/rawmidi.c | 20 ++++++++++++++++++++
6 files changed, 46 insertions(+), 1 deletion(-)

--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -1436,6 +1436,8 @@ static ssize_t snd_ctl_read(struct file
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);
--- a/sound/core/hwdep.c
+++ b/sound/core/hwdep.c
@@ -131,6 +131,10 @@ static int snd_hwdep_open(struct inode *
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;
@@ -462,12 +466,15 @@ static int snd_hwdep_dev_disconnect(stru
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;
}
--- 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
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;
--- a/sound/core/pcm.c
+++ b/sound/core/pcm.c
@@ -1087,12 +1087,16 @@ static int snd_pcm_dev_disconnect(struct
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) {
snd_pcm_stream_lock_irq(substream);
- if (substream->runtime)
+ 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) {
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -1508,6 +1508,10 @@ static int snd_pcm_drain(struct snd_pcm_
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;
@@ -2158,6 +2162,10 @@ static int snd_pcm_open(struct file *fil
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;
--- a/sound/core/rawmidi.c
+++ b/sound/core/rawmidi.c
@@ -424,6 +424,10 @@ static int snd_rawmidi_open(struct inode
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;
@@ -995,6 +999,8 @@ static ssize_t snd_rawmidi_read(struct f
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)
@@ -1238,6 +1244,8 @@ static ssize_t snd_rawmidi_write(struct
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)
@@ -1613,9 +1621,20 @@ static int snd_rawmidi_dev_register(stru
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]) {
@@ -1630,6 +1649,7 @@ static int snd_rawmidi_dev_disconnect(st
}
#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;
}


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