mirrors/alsa-lib
1
0
Fork 0
mirror of https://github.com/alsa-project/alsa-lib.git synced 2025-10-29 05:40:25 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

pcm: dmix: resume workaround for buggy driver

Browse source 
The previous commit removed the whole handling of resume in dmix, but
this seems causing another regression; some buggy drivers assume that
the device-resume needs to be triggered before transitioning to
PREPARED state.  As an ugly workaround, in this patch, when the slave
PCM supports resume, snd_pcm_direct_resume() does resume of the slave
PCM but immediately drop the stream after that.  In that way, the
device is brought to the sane active state, then the apps can prepare
and restart the stream properly.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2016-05-25 15:03:51 +02:00
parent 2fa36eb03c
commit 6d1d620ead
1 changed files with 24 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

25
src/pcm/pcm_direct.c
View file

@ -837,6 +837,27 @@ int snd_pcm_direct_prepare(snd_pcm_t *pcm)
int snd_pcm_direct_resume(snd_pcm_t *pcm)
{
snd_pcm_direct_t *dmix = pcm->private_data;
snd_pcm_t *spcm = dmix->spcm;
snd_pcm_direct_semaphore_down(dmix, DIRECT_IPC_SEM_CLIENT);
/* some buggy drivers require the device resumed before prepared;
* when a device has RESUME flag and is in SUSPENDED state, resume
* here but immediately drop to bring it to a sane active state.
*/
if ((spcm->info & SND_PCM_INFO_RESUME) &&
snd_pcm_state(spcm) == SND_PCM_STATE_SUSPENDED) {
snd_pcm_resume(spcm);
snd_pcm_drop(spcm);
snd_pcm_direct_timer_stop(dmix);
snd_pcm_direct_clear_timer_queue(dmix);
snd_pcm_areas_silence(snd_pcm_mmap_areas(spcm), 0,
spcm->channels, spcm->buffer_size,
spcm->format);
snd_pcm_prepare(spcm);
snd_pcm_start(spcm);
}
snd_pcm_direct_semaphore_up(dmix, DIRECT_IPC_SEM_CLIENT);
return -ENOSYS;
}
@ -845,7 +866,7 @@ int snd_pcm_direct_resume(snd_pcm_t *pcm)
/* copy the slave setting */
static void save_slave_setting(snd_pcm_direct_t *dmix, snd_pcm_t *spcm)
{
spcm->info &= ~(SND_PCM_INFO_PAUSE | SND_PCM_INFO_RESUME);
spcm->info &= ~SND_PCM_INFO_PAUSE;
COPY_SLAVE(access);
COPY_SLAVE(format);
@ -874,6 +895,8 @@ static void save_slave_setting(snd_pcm_direct_t *dmix, snd_pcm_t *spcm)
COPY_SLAVE(buffer_time);
COPY_SLAVE(sample_bits);
COPY_SLAVE(frame_bits);
dmix->shmptr->s.info &= ~SND_PCM_INFO_RESUME;
}
#undef COPY_SLAVE