linux/sound
Stephan Gerhold 7f2430cda8
ASoC: qcom: q6asm-dai: Add SNDRV_PCM_INFO_BATCH flag
At the moment, playing audio with PulseAudio with the qdsp6 driver
results in distorted sound. It seems like its timer-based scheduling
does not work properly with qdsp6 since setting tsched=0 in
the PulseAudio configuration avoids the issue.

Apparently this happens when the pointer() callback is not accurate
enough. There is a SNDRV_PCM_INFO_BATCH flag that can be used to stop
PulseAudio from using timer-based scheduling by default.

According to https://www.alsa-project.org/pipermail/alsa-devel/2014-March/073816.html:

    The flag is being used in the sense explained in the previous audio
    meeting -- the data transfer granularity isn't fine enough but aligned
    to the period size (or less).

q6asm-dai reports the position as multiple of

    prtd->pcm_count = snd_pcm_lib_period_bytes(substream)

so it indeed just a multiple of the period size.

Therefore adding the flag here seems appropriate and makes audio
work out of the box.

Fixes: 2a9e92d371 ("ASoC: qdsp6: q6asm: Add q6asm dai driver")
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20200330175210.47518-1-stephan@gerhold.net
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-31 19:23:54 +01:00
..
ac97 ALSA: ac97: Constify snd_ac97_bus_ops definitions 2020-01-03 09:24:11 +01:00
aoa ALSA: aoa: More constifications 2020-01-05 16:14:27 +01:00
arm ASoC: arm: use asoc_rtd_to_cpu() / asoc_rtd_to_codec() macro for DAI pointer 2020-03-27 14:44:56 +00:00
atmel ALSA: atmel: Constify snd_ac97_bus_ops definitions 2020-01-03 09:24:12 +01:00
core Linux 5.6-rc5 2020-03-11 18:45:26 +00:00
drivers sound fixes for 5.6-rc1 2020-02-06 14:15:01 +00:00
firewire Merge branch 'for-linus' into for-next 2020-01-20 11:44:51 +01:00
hda ASoC: Fixes for v5.6 2020-02-18 13:33:39 +01:00
i2c ALSA: i2c: Constify snd_kcontrol_new items 2020-01-03 09:24:24 +01:00
isa sound updates for 5.6-rc1 2020-01-28 16:26:57 -08:00
mips ALSA: sgio2audio: Remove usage of dropped hw_params/hw_free functions 2020-03-06 12:06:41 +01:00
oss compat_ioctl: remove translation for sound ioctls 2019-10-23 17:23:45 +02:00
parisc sound updates for 5.6-rc1 2020-01-28 16:26:57 -08:00
pci ALSA: hda/realtek - Enable the headset of ASUS B9450FA with ALC294 2020-03-05 15:46:54 +01:00
pcmcia ALSA: pdaudiocf: More constification 2020-01-05 16:15:13 +01:00
ppc ALSA: ppc: More constifications 2020-01-05 16:14:43 +01:00
sh ALSA: sh: Fix compile warning wrt const 2020-01-05 16:15:14 +01:00
soc ASoC: qcom: q6asm-dai: Add SNDRV_PCM_INFO_BATCH flag 2020-03-31 19:23:54 +01:00
sparc ALSA: sparc: More constifications 2020-01-05 16:14:56 +01:00
spi ALSA: spi: More constification 2020-01-05 16:15:13 +01:00
synth ALSA: emux: More constifications 2020-01-05 16:14:46 +01:00
usb Linux 5.6-rc5 2020-03-11 18:45:26 +00:00
x86 sound updates for 5.6-rc1 2020-01-28 16:26:57 -08:00
xen ALSA: xen: Drop superfluous ioctl PCM ops 2019-12-11 07:25:35 +01:00
ac97_bus.c ALSA: ac97: Treat snd_ac97_bus_ops as const 2020-01-03 09:24:08 +01:00
Kconfig
last.c
Makefile
sound_core.c sound: fix a memory leak bug 2019-08-08 08:18:32 +02:00