From 2a7fa96feddb63d36d64336a994dc4132e8a5cd4 Mon Sep 17 00:00:00 2001 From: Shengjiu Wang Date: Mon, 29 Dec 2014 13:40:08 +0800 Subject: [PATCH] MLK-9974: ASoC: fsl_sai: There is underrun detected in the beginning sometimes Write initial words to SAI FIFO to reduce underrun error Signed-off-by: Shengjiu Wang (cherry picked from commit 7ba8ae883d84540fac5ed4147d124399537bc0b3) (cherry picked from commit f4435f35aa2a97551d2c4a12ca316c354a880f85) --- sound/soc/fsl/fsl_sai.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/sound/soc/fsl/fsl_sai.c +++ b/sound/soc/fsl/fsl_sai.c @@ -506,7 +506,9 @@ static int fsl_sai_trigger(struct snd_pc { struct fsl_sai *sai = snd_soc_dai_get_drvdata(cpu_dai); bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK; + u8 channels = substream->runtime->channels; u32 xcsr, count = 100; + int i; /* * Asynchronous mode: Clear SYNC for both Tx and Rx. @@ -529,6 +531,11 @@ static int fsl_sai_trigger(struct snd_pc regmap_update_bits(sai->regmap, FSL_SAI_xCSR(tx), FSL_SAI_CSR_FRDE, FSL_SAI_CSR_FRDE); + for (i = 0; tx && i < channels; i++) + regmap_write(sai->regmap, FSL_SAI_TDR, 0x0); + if (tx) + udelay(10); + regmap_update_bits(sai->regmap, FSL_SAI_RCSR, FSL_SAI_CSR_TERE, FSL_SAI_CSR_TERE); regmap_update_bits(sai->regmap, FSL_SAI_TCSR,