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

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Message-ID: <14f167e6-ea2f-401a-87e9-2722929bd9a2@linaro.org>
Date: Mon, 3 Feb 2025 14:12:36 +0000
From: Srinivas Kandagatla <srinivas.kandagatla@...aro.org>
To: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
Cc: broonie@...nel.org, 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
Subject: Re: [PATCH] ASoC: q6apm-dai: schedule all the periods before we start
 streaming



On 03/02/2025 14:09, Dmitry Baryshkov wrote:
> On Mon, Feb 03, 2025 at 12:49:45PM +0000, srinivas.kandagatla@...aro.org wrote:
>> 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);
> 
> So, all errors except the last one are ignored now?

this needs fixing,

thanks for review
--srini
> 
>> +		}
>>   		break;
>>   	case SNDRV_PCM_TRIGGER_STOP:
>>   		/* TODO support be handled via SoftPause Module */
>> -- 
>> 2.39.5
>>
>