staging: vc4_services: bcm2835-audio: Add SNDRV_PCM_INFO_BATCH flag

Playing audio with PulseAudio and the bcm2835-pcm driver results
in distorted sound. Timer-based scheduling does not properly work
with bcm2835-pcm since configuring PulseAudio with tsched=0
avoids this problem.

Setting the SNDRV_PCM_INFO_BATCH flag prevents PulseAudio to use
timer-based scheduling by default. Settings this flag makes audio
works out of the box.

Based on: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7f2430cda819a9ecb1df5a0f3ef4f1c20db3f811

Signed-off-by: Dylan Van Assche <me@dylanvanassche.be>
Link: https://lore.kernel.org/r/20210127174348.10192-1-me@dylanvanassche.be
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Dylan Van Assche 2021-01-27 18:43:48 +01:00 committed by Greg Kroah-Hartman
parent d730b1e1c3
commit 684ceb81dc

View file

@ -12,7 +12,7 @@
static const struct snd_pcm_hardware snd_bcm2835_playback_hw = {
.info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
SNDRV_PCM_INFO_SYNC_APPLPTR),
SNDRV_PCM_INFO_SYNC_APPLPTR | SNDRV_PCM_INFO_BATCH),
.formats = SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S16_LE,
.rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_48000,
.rate_min = 8000,
@ -29,7 +29,7 @@ static const struct snd_pcm_hardware snd_bcm2835_playback_hw = {
static const struct snd_pcm_hardware snd_bcm2835_playback_spdif_hw = {
.info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
SNDRV_PCM_INFO_SYNC_APPLPTR),
SNDRV_PCM_INFO_SYNC_APPLPTR | SNDRV_PCM_INFO_BATCH),
.formats = SNDRV_PCM_FMTBIT_S16_LE,
.rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_44100 |
SNDRV_PCM_RATE_48000,