This is a note to let you know that I've just added the patch titled
ASoC: fsl: imx-pcm-rpmsg: Add SNDRV_PCM_INFO_BATCH flag
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
asoc-fsl-imx-pcm-rpmsg-add-sndrv_pcm_info_batch-flag.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 90474b90330a6c55545510cb91b6ef0cda3e212b
Author: Shengjiu Wang <shengjiu.wang@xxxxxxx>
Date: Mon Sep 11 14:38:07 2023 +0800
ASoC: fsl: imx-pcm-rpmsg: Add SNDRV_PCM_INFO_BATCH flag
[ Upstream commit 2f9426905a63be7ccf8cd10109caf1848aa0993a ]
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@xxxxxxx>
Link: https://lore.kernel.org/r/1694414287-13291-1-git-send-email-shengjiu.wang@xxxxxxx
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/sound/soc/fsl/imx-pcm-rpmsg.c b/sound/soc/fsl/imx-pcm-rpmsg.c
index 35049043e5322..933bac7ea1864 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 |
