linux-kernel - [PATCH] ASoC: q6apm-dai: schedule all the periods before we start streaming

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Message-Id: <20250203124945.11406-1-srinivas.kandagatla@linaro.org>
Date: Mon,  3 Feb 2025 12:49:45 +0000
From: srinivas.kandagatla@...aro.org
To: broonie@...nel.org
Cc: lgirdwood@...il.com,
	perex@...ex.cz,
	tiwai@...e.com,
	krzysztof.kozlowski@...aro.org,
	pierre-louis.bossart@...ux.dev,
	linux-sound@...r.kernel.org,
	linux-arm-msm@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	dmitry.baryshkov@...aro.org,
	Srinivas Kandagatla <srinivas.kandagatla@...aro.org>
Subject: [PATCH] ASoC: q6apm-dai: schedule all the periods before we start streaming

From: Srinivas Kandagatla <srinivas.kandagatla@...aro.org>

With the existing code, we are only setting up one period at a time, in a
ping-pong buffer style. This tiggers lot of underruns in the dsp
leading to jitter noise during audio playback.

Fix this by scheduling all the periods, this will ensure that the dsp
has enough buffer feed and ultimatley fixing the underruns and audio
distortion.

Fixes: 9b4fe0f1cd79 ("ASoC: qdsp6: audioreach: add q6apm-dai support")
Reported-by: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@...aro.org>
---
 sound/soc/qcom/qdsp6/q6apm-dai.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/sound/soc/qcom/qdsp6/q6apm-dai.c b/sound/soc/qcom/qdsp6/q6apm-dai.c
index c9404b5934c7..148c3fb77168 100644
--- a/sound/soc/qcom/qdsp6/q6apm-dai.c
+++ b/sound/soc/qcom/qdsp6/q6apm-dai.c
@@ -299,15 +299,17 @@ static int q6apm_dai_trigger(struct snd_soc_component *component,
 {
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct q6apm_dai_rtd *prtd = runtime->private_data;
-	int ret = 0;
+	int ret = 0, i;
 
 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
 	case SNDRV_PCM_TRIGGER_RESUME:
 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 		 /* start writing buffers for playback only as we already queued capture buffers */
-		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
-			ret = q6apm_write_async(prtd->graph, prtd->pcm_count, 0, 0, 0);
+		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+			for (i = 0; i < runtime->periods; i++)
+				ret = q6apm_write_async(prtd->graph, prtd->pcm_count, 0, 0, 0);
+		}
 		break;
 	case SNDRV_PCM_TRIGGER_STOP:
 		/* TODO support be handled via SoftPause Module */
-- 
2.39.5