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ALSA: pcm: Don't add internal PCMs to PCM device list

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An internal PCM object shouldn't be added to the PCM device list, as
it's never accessed directly from the user-space, and it has no proc
or any similar accesses.  Currently, it's excluded in snd_pcm_get()
and snd_pcm_next(), but it's easier not to add such an object to the
list.

Actually, the whole snd_pcm_dev_register() can be skipped for an
internal PCM.  So this patch changes the code there, but also
addresses the uninitialized list_head access.

Acked-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2015-02-20 16:49:04 +01:00
parent ad876c8622
commit b95bd3a454
1 changed files with 16 additions and 15 deletions
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31
sound/core/pcm.c
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@ -49,8 +49,6 @@ static struct snd_pcm *snd_pcm_get(struct snd_card *card, int device)
struct snd_pcm *pcm;
list_for_each_entry(pcm, &snd_pcm_devices, list) {
if (pcm->internal)
continue;
if (pcm->card == card && pcm->device == device)
return pcm;
}
@ -62,8 +60,6 @@ static int snd_pcm_next(struct snd_card *card, int device)
struct snd_pcm *pcm;
list_for_each_entry(pcm, &snd_pcm_devices, list) {
if (pcm->internal)
continue;
if (pcm->card == card && pcm->device > device)
return pcm->device;
else if (pcm->card->number > card->number)
@ -76,6 +72,9 @@ static int snd_pcm_add(struct snd_pcm *newpcm)
{
struct snd_pcm *pcm;
if (newpcm->internal)
return 0;
list_for_each_entry(pcm, &snd_pcm_devices, list) {
if (pcm->card == newpcm->card && pcm->device == newpcm->device)
return -EBUSY;
@ -782,6 +781,9 @@ static int _snd_pcm_new(struct snd_card *card, const char *id, int device,
pcm->card = card;
pcm->device = device;
pcm->internal = internal;
mutex_init(&pcm->open_mutex);
init_waitqueue_head(&pcm->open_wait);
INIT_LIST_HEAD(&pcm->list);
if (id)
strlcpy(pcm->id, id, sizeof(pcm->id));
if ((err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK, playback_count)) < 0) {
@ -792,8 +794,6 @@ static int _snd_pcm_new(struct snd_card *card, const char *id, int device,
snd_pcm_free(pcm);
return err;
}
mutex_init(&pcm->open_mutex);
init_waitqueue_head(&pcm->open_wait);
if ((err = snd_device_new(card, SNDRV_DEV_PCM, pcm, &ops)) < 0) {
snd_pcm_free(pcm);
return err;
@ -1075,15 +1075,16 @@ static int snd_pcm_dev_register(struct snd_device *device)
if (snd_BUG_ON(!device || !device->device_data))
return -ENXIO;
pcm = device->device_data;
if (pcm->internal)
return 0;
mutex_lock(&register_mutex);
err = snd_pcm_add(pcm);
if (err) {
mutex_unlock(&register_mutex);
return err;
}
if (err)
goto unlock;
for (cidx = 0; cidx < 2; cidx++) {
int devtype = -1;
if (pcm->streams[cidx].substream == NULL || pcm->internal)
if (pcm->streams[cidx].substream == NULL)
continue;
switch (cidx) {
case SNDRV_PCM_STREAM_PLAYBACK:
@ -1098,9 +1099,8 @@ static int snd_pcm_dev_register(struct snd_device *device)
&snd_pcm_f_ops[cidx], pcm,
&pcm->streams[cidx].dev);
if (err < 0) {
list_del(&pcm->list);
mutex_unlock(&register_mutex);
return err;
list_del_init(&pcm->list);
goto unlock;
}
for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
@ -1110,8 +1110,9 @@ static int snd_pcm_dev_register(struct snd_device *device)
list_for_each_entry(notify, &snd_pcm_notify_list, list)
notify->n_register(pcm);
unlock:
mutex_unlock(&register_mutex);
return 0;
return err;
}
static int snd_pcm_dev_disconnect(struct snd_device *device)