RE: [PATCH] ASoC: nau8825: fix issue that pop noise when start capture

[Kumar, Abhijeet]

Need some help on next steps 
Who will do the review and patch merge?
Should i add any other mailing list to this thread?


-----Original Message-----
From: John Hsu [mailto:KCHSU0@xxxxxxxxxxx] 
Sent: Friday, December 15, 2017 12:47 PM
To: Kumar, Abhijeet <abhijeet.kumar@xxxxxxxxx>
Cc: Liam Girdwood <lgirdwood@xxxxxxxxx>; Mark Brown <broonie@xxxxxxxxxx>; Jaroslav Kysela <perex@xxxxxxxx>; Takashi Iwai <tiwai@xxxxxxxx>; Bhumika Goyal <bhumirks@xxxxxxxxx>; alsa-devel@xxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; anatol.pomozov@xxxxxxxxx; mhkuo@xxxxxxxxxxx; wuchengli@xxxxxxxxxx; cychiang@xxxxxxxxxx; Chiang, Mac <mac.chiang@xxxxxxxxx>; YHCHuang@xxxxxxxxxxx; CTLIN0@xxxxxxxxxxx; WTLI@xxxxxxxxxxx
Subject: Re: [PATCH] ASoC: nau8825: fix issue that pop noise when start capture

On 12/12/2017 3:10 AM, abhijeet.kumar@xxxxxxxxx wrote:
> From: Abhijeet Kumar <abhijeet.kumar@xxxxxxxxx>
>
> In skylake platform, we hear a loud pop noise(0 dB) at start of audio 
> capture power up sequence. This patch removes the pop noise from the 
> recording by adding a delay before enabling ADC.
>
> Signed-off-by: Abhijeet Kumar <abhijeet.kumar@xxxxxxxxx>
> ---
>  sound/soc/codecs/nau8825.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/sound/soc/codecs/nau8825.c b/sound/soc/codecs/nau8825.c 
> index 714ce17da717..e853a6dfd33b 100644
> --- a/sound/soc/codecs/nau8825.c
> +++ b/sound/soc/codecs/nau8825.c
> @@ -905,6 +905,7 @@ static int nau8825_adc_event(struct 
> snd_soc_dapm_widget *w,
>
>       switch (event) {
>       case SND_SOC_DAPM_POST_PMU:
> +             msleep(125);
>               regmap_update_bits(nau8825->regmap, NAU8825_REG_ENA_CTRL,
>                       NAU8825_ENABLE_ADC, NAU8825_ENABLE_ADC);
>               break;

The solution is fine for me. It's verified in my device and indeed helps to reduce the capture pop noise. I think the little delay is acceptable.



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