On capture through dmic we observe a glitch at the start of record. This is because we start capturing even before dmic is ready to send out data. The glitch seen last for ~20msec. Signed-off-by: Akshu Agrawal <akshu.agrawal@xxxxxxx> Signed-off-by: Daniel Kurtz <djkurtz@xxxxxxxxxxxx> --- sound/soc/amd/acp-da7219-max98357a.c | 28 ++++++++++++++++++++++++++-- 1 file changed, 26 insertions(+), 2 deletions(-) diff --git a/sound/soc/amd/acp-da7219-max98357a.c b/sound/soc/amd/acp-da7219-max98357a.c index a5daad9..72b1cf4 100644 --- a/sound/soc/amd/acp-da7219-max98357a.c +++ b/sound/soc/amd/acp-da7219-max98357a.c @@ -44,6 +44,8 @@ #define CZ_PLAT_CLK 48000000 #define DUAL_CHANNEL 2 +#define ADAU7002_DELAY_MS 20 + static struct snd_soc_jack cz_jack; static struct clk *da7219_dai_clk; @@ -213,6 +215,7 @@ static int cz_dmic0_startup(struct snd_pcm_substream *substream) struct snd_soc_pcm_runtime *rtd = substream->private_data; struct snd_soc_card *card = rtd->card; struct acp_platform_info *machine = snd_soc_card_get_drvdata(card); + int ret; /* * On this platform for PCM device we support stereo @@ -225,7 +228,17 @@ static int cz_dmic0_startup(struct snd_pcm_substream *substream) &constraints_rates); machine->cap_i2s_instance = I2S_BT_INSTANCE; - return da7219_clk_enable(substream); + ret = da7219_clk_enable(substream); + if (ret) + return ret; + /* + * On some platforms, it takes ~20 msec for PDM DMICs and ADAU7002 + * to settle and start producing proper audio data. + */ + msleep(ADAU7002_DELAY_MS); + /* Delay in frames for 48Khz, 16bit, 2 channel */ + runtime->delay = ADAU7002_DELAY_MS * 48; + return 0; } static int cz_dmic1_startup(struct snd_pcm_substream *substream) @@ -234,6 +247,7 @@ static int cz_dmic1_startup(struct snd_pcm_substream *substream) struct snd_soc_pcm_runtime *rtd = substream->private_data; struct snd_soc_card *card = rtd->card; struct acp_platform_info *machine = snd_soc_card_get_drvdata(card); + int ret; /* * On this platform for PCM device we support stereo @@ -247,7 +261,17 @@ static int cz_dmic1_startup(struct snd_pcm_substream *substream) machine->cap_i2s_instance = I2S_SP_INSTANCE; machine->capture_channel = CAP_CHANNEL0; - return da7219_clk_enable(substream); + ret = da7219_clk_enable(substream); + if (ret) + return ret; + /* + * On some platforms, it takes ~20 msec for PDM DMICs and ADAU7002 + * to settle and start producing proper audio data. + */ + msleep(ADAU7002_DELAY_MS); + /* Delay in frames for 48Khz, 16bit, 2 channel */ + runtime->delay = ADAU7002_DELAY_MS * 48; + return 0; } static void cz_dmic_shutdown(struct snd_pcm_substream *substream) -- 1.9.1 _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
