Commit 684ceb81 authored by Dylan Van Assche's avatar Dylan Van Assche Committed by Greg Kroah-Hartman
Browse files

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: default avatarDylan Van Assche <me@dylanvanassche.be>
Link: https://lore.kernel.org/r/20210127174348.10192-1-me@dylanvanassche.be


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d730b1e1

drivers/staging/vc04_services/bcm2835-audio/bcm2835-pcm.c

+2 −2
Original line number Diff line number Diff line
@@ -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,