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From: Shengjiu Wang <shengjiu.wang@nxp.com>
To: pierre-louis.bossart@linux.intel.com,
	lgirdwood@gmail.com,
	peter.ujfalusi@linux.intel.com,
	yung-chuan.liao@linux.intel.com,
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	tiwai@suse.com,
	shawnguo@kernel.org,
	s.hauer@pengutronix.de,
	kernel@pengutronix.de,
	festevam@gmail.com,
	linux-imx@nxp.com,
	sound-open-firmware@alsa-project.org,
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	shengjiu.wang@gmail.com
Subject: [PATCH] ASoC: SOF: imx: Add SNDRV_PCM_INFO_BATCH flag
Date: Wed, 27 Dec 2023 17:27:43 +0800
Message-Id: <1703669263-13832-1-git-send-email-shengjiu.wang@nxp.com>
Precedence: bulk

The sof imx 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 sof 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/sof/imx/imx8.c    | 1 +
 sound/soc/sof/imx/imx8m.c   | 1 +
 sound/soc/sof/imx/imx8ulp.c | 1 +
 3 files changed, 3 insertions(+)

diff --git a/sound/soc/sof/imx/imx8.c b/sound/soc/sof/imx/imx8.c
index 170740bce839..d777e70250ef 100644
--- a/sound/soc/sof/imx/imx8.c
+++ b/sound/soc/sof/imx/imx8.c
@@ -603,6 +603,7 @@ static struct snd_sof_dsp_ops sof_imx8x_ops = {
 			SNDRV_PCM_INFO_MMAP_VALID |
 			SNDRV_PCM_INFO_INTERLEAVED |
 			SNDRV_PCM_INFO_PAUSE |
+			SNDRV_PCM_INFO_BATCH |
 			SNDRV_PCM_INFO_NO_PERIOD_WAKEUP
 };
 
diff --git a/sound/soc/sof/imx/imx8m.c b/sound/soc/sof/imx/imx8m.c
index f088fd1a672b..1b976fa500aa 100644
--- a/sound/soc/sof/imx/imx8m.c
+++ b/sound/soc/sof/imx/imx8m.c
@@ -472,6 +472,7 @@ static struct snd_sof_dsp_ops sof_imx8m_ops = {
 		SNDRV_PCM_INFO_MMAP_VALID |
 		SNDRV_PCM_INFO_INTERLEAVED |
 		SNDRV_PCM_INFO_PAUSE |
+		SNDRV_PCM_INFO_BATCH |
 		SNDRV_PCM_INFO_NO_PERIOD_WAKEUP,
 };
 
diff --git a/sound/soc/sof/imx/imx8ulp.c b/sound/soc/sof/imx/imx8ulp.c
index ca6edb85ff71..2badca75782b 100644
--- a/sound/soc/sof/imx/imx8ulp.c
+++ b/sound/soc/sof/imx/imx8ulp.c
@@ -463,6 +463,7 @@ static struct snd_sof_dsp_ops sof_imx8ulp_ops = {
 			SNDRV_PCM_INFO_MMAP_VALID |
 			SNDRV_PCM_INFO_INTERLEAVED |
 			SNDRV_PCM_INFO_PAUSE |
+			SNDRV_PCM_INFO_BATCH |
 			SNDRV_PCM_INFO_NO_PERIOD_WAKEUP,
 
 	/* PM */
-- 
2.34.1