[PATCH] ASoC: fsl: imx-pcm-rpmsg: Add SNDRV_PCM_INFO_BATCH flag

[PATCH] ASoC: fsl: imx-pcm-rpmsg: Add SNDRV_PCM_INFO_BATCH flag

[Shengjiu Wang]

The rpmsg pcm device is a device which should support
double buffering.

Found this issue with pipewire. When there is no
SNDRV_PCM_INFO_BATCH flag in driver, the pipewire will
set headroom to be zero, and because rpmsg pcm device
don't support residue report, when the latency setting
is small, the "delay" always larger than "target" in
alsa-pcm.c, that reading next period data is not
scheduled on time.

With SNDRV_PCM_INFO_BATCH flag in driver, the pipewire
will select a smaller period size for device, then
the task of reading next period data will be scheduled
on time.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
---
 sound/soc/fsl/imx-pcm-rpmsg.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sound/soc/fsl/imx-pcm-rpmsg.c b/sound/soc/fsl/imx-pcm-rpmsg.c
index d63782b8bdef..bb736d45c9e0 100644
--- a/sound/soc/fsl/imx-pcm-rpmsg.c
+++ b/sound/soc/fsl/imx-pcm-rpmsg.c
@@ -19,6 +19,7 @@
 static struct snd_pcm_hardware imx_rpmsg_pcm_hardware = {
 	.info = SNDRV_PCM_INFO_INTERLEAVED |
 		SNDRV_PCM_INFO_BLOCK_TRANSFER |
+		SNDRV_PCM_INFO_BATCH |
 		SNDRV_PCM_INFO_MMAP |
 		SNDRV_PCM_INFO_MMAP_VALID |
 		SNDRV_PCM_INFO_NO_PERIOD_WAKEUP |
-- 
2.34.1

Re: [PATCH] ASoC: fsl: imx-pcm-rpmsg: Add SNDRV_PCM_INFO_BATCH flag

[Mark Brown]

On Mon, 11 Sep 2023 14:38:07 +0800, Shengjiu Wang wrote:
> The rpmsg pcm device is a device which should support
> double buffering.
> 
> Found this issue with pipewire. When there is no
> SNDRV_PCM_INFO_BATCH flag in driver, the pipewire will
> set headroom to be zero, and because rpmsg pcm device
> don't support residue report, when the latency setting
> is small, the "delay" always larger than "target" in
> alsa-pcm.c, that reading next period data is not
> scheduled on time.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next

Thanks!

[1/1] ASoC: fsl: imx-pcm-rpmsg: Add SNDRV_PCM_INFO_BATCH flag
      commit: 2f9426905a63be7ccf8cd10109caf1848aa0993a

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark