[PATCH 4.9 17/56] ASoC: nau8825: fix issue that pop noise when start capture

From: Greg Kroah-Hartman
Date: Fri Mar 02 2018 - 05:11:05 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Abhijeet Kumar <abhijeet.kumar@xxxxxxxxx>


[ Upstream commit d070f7c703ef26e3db613f24206823f916272fc6 ]

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>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
sound/soc/codecs/nau8825.c | 1 +
1 file changed, 1 insertion(+)

--- a/sound/soc/codecs/nau8825.c
+++ b/sound/soc/codecs/nau8825.c
@@ -882,6 +882,7 @@ static int nau8825_adc_event(struct snd_

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;