ASoC: fsl: imx-pcm-rpmsg: Add SNDRV_PCM_INFO_BATCH flag

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>
Link: https://lore.kernel.org/r/1694414287-13291-1-git-send-email-shengjiu.wang@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/fsl/imx-pcm-rpmsg.c b/sound/soc/fsl/imx-pcm-rpmsg.c
index d63782b8bdef8f8b27d9669dabdc550cd0445f5a..bb736d45c9e04e5de7de46698d55b1b16b5a8718 100644 (file)
--- 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 |