[TGL][DSM] pop noise happens at the beginning of recording when playback is triggered first

Describe the bug
when testing DSM, there's a sharp pop noise at the beginning of recording, this issue only happens when playback is triggered first, delay for a few seconds then trigger capture, you will hear that pop noise. But this pop noise was not captured in the wav file. the waveform of 4 channels are pure, even at the beginning.

To Reproduce

Enable loopback mode for DSM
run:
amp_enable.sh.txt
Trigger playback on speaker:

aplay -Dhw:0,0 -f s32_le -c 2 -r 48000 sine_48k_32bit.wav &

Delay for a few seconds

sleep 2

Trigger capture on speaker

arecord -Dhw:0,0 -f s32_le -c 4 -r 48000 dsm.wav

Reproduction Rate
10/10

Expected behavior
no pop noise.

Environment
Driver: fce7f93 + #1971 + https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git/commit/?h=for-next&id=914f674bec6efe42f9d6b036850a618fd1698290
Firmware:
SOF branch: tgl-005-drop-stable Commit: 277a9717
TPLG: sof-tgl-max98373-rt5682.tplg

dsm_dmesg.txt
dsm-logger.txt

@sathya-nujella

This could be Max98373 configuration issue, as there is no change of the data(channel L/R) transmitting from the ASoC SSP to the codec (no noise in the captured file proved this), @sathya-nujella can Dhara help to check this with Maxim engineer, I can't assign this to Dhara as she is not in the SOF group, so assigning it to you.

@keyonjie

Sure @keyonjie.

I am not able to assign to Dhara. Not sure what is the issue. When I search for her ID in assignee field.. it does not show up.
Can you please help why it is happening: this is her GH: https://github.com/RDharageswari

@sathya-nujella

@sathya-nujella please ask Dhara to join the sof-developers team: https://github.com/orgs/thesofproject/people

@lgirdwood do we need invitation for that?

@RDharageswari

Adding @RDharageswari

@naveen-manohar

Thanks @naveen-manohar, i couldnt subscribe to the group.

was able to capture the register dump when the issue happened.
exactly During the pop noise I see that the register 0x2024, has a value 0xd8 initially and changes to 0x98 later. Bit 6 & 7 corresponds to PCM_DATA_WIDTH[1:0] . [10 : 24-bit] & [11: 32 bit]. SSP1 on which the playback was ongoing was initially 32bit and when the capture started it changed to 24bit . Both pb & capture share the same I2S bus . this change can cause pop noise. Debugging WIP

@RDharageswari

good finding @RDharageswari .
maybe worth to try setting to 24/25 bit in below snippet for a quick try:

static int max98373_hw_params(struct snd_pcm_substream *substream,
			      struct snd_pcm_hw_params *params)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_soc_dai *codec_dai;
	int j;

	for_each_rtd_codec_dais(rtd, j, codec_dai) {
		if (!strcmp(codec_dai->component->name, MAX_98373_DEV0_NAME)) {
			/* DEV0 tdm slot configuration */
-			snd_soc_dai_set_tdm_slot(codec_dai, 0x3, 0x1, 8, 32);
+			snd_soc_dai_set_tdm_slot(codec_dai, 0x3, 0x1, 8, 25);

		}
		if (!strcmp(codec_dai->component->name, MAX_98373_DEV1_NAME)) {
			/* DEV1 tdm slot configuration */
-			snd_soc_dai_set_tdm_slot(codec_dai, 0xC, 0x2, 8, 32);
+			snd_soc_dai_set_tdm_slot(codec_dai, 0xC, 0x2, 8, 25);

		}
	}
	return 0;
}

This worked for me.
static int max98373_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params)
{
struct snd_soc_pcm_runtime *rtd = substream->private_data;
struct snd_soc_dai *codec_dai;
int j;

for_each_rtd_codec_dais(rtd, j, codec_dai) {
	if (!strcmp(codec_dai->component->name, MAX_98373_DEV0_NAME)) {
		/* DEV0 tdm slot configuration */

  	snd_soc_dai_set_tdm_slot(codec_dai, 0x3, 0x1, 8, 32);

  	snd_soc_dai_set_tdm_slot(codec_dai, 0x3, 0x1, 8, 24);

  }
  if (!strcmp(codec_dai->component->name, MAX_98373_DEV1_NAME)) {
  	/* DEV1 tdm slot configuration */

  	snd_soc_dai_set_tdm_slot(codec_dai, 0xC, 0x2, 8, 32);

  	snd_soc_dai_set_tdm_slot(codec_dai, 0xC, 0x2, 8, 24);

  }

}
return 0;
}

um, seems the codec doesn't accept 25 bit slot_width, no sure if the unaligned with the FW(25 bit slot_width) side will introduce noise.

This patch fixes the issue:
ebdfc36

The above patch needs coreboot changes as well
https://review.coreboot.org/c/coreboot/+/41216/22/src/mainboard/google/volteer/variants/volteer/overridetree.cb#19

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[TGL][DSM] pop noise happens at the beginning of recording when playback is triggered first #2054

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[TGL][DSM] pop noise happens at the beginning of recording when playback is triggered first #2054

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keyonjie commented on Apr 28, 2020

sathya-nujella commented on Apr 28, 2020

keyonjie commented on Apr 28, 2020

naveen-manohar commented on Apr 28, 2020

RDharageswari commented on Apr 28, 2020

RDharageswari commented on Apr 29, 2020

keyonjie commented on Apr 29, 2020

RDharageswari commented on Apr 29, 2020

keyonjie commented on Apr 29, 2020

RDharageswari commented on Jun 6, 2020

RDharageswari commented on Jun 6, 2020

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