From: Nicolin Chen Guangyu.Chen@freescale.com
TE/RE bit of T/RCSR will remain set untill the current frame is physically finished. The FIFO reset operation should wait this bit's totally cleared rather than ignoring its status which might cause TE/RE disabling failed.
This patch adds delay and timeout to wait for its completion before FIFO reset.
Signed-off-by: Nicolin Chen nicoleotsuka@gmail.com --- sound/soc/fsl/fsl_sai.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-)
diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c index a437899..a79a9b0 100644 --- a/sound/soc/fsl/fsl_sai.c +++ b/sound/soc/fsl/fsl_sai.c @@ -327,7 +327,7 @@ static int fsl_sai_trigger(struct snd_pcm_substream *substream, int cmd, { struct fsl_sai *sai = snd_soc_dai_get_drvdata(cpu_dai); bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK; - u32 xcsr; + u32 xcsr, count = 100;
/* * The transmitter bit clock and frame sync are to be @@ -369,11 +369,20 @@ static int fsl_sai_trigger(struct snd_pcm_substream *substream, int cmd, if (!(xcsr & FSL_SAI_CSR_FRDE)) { /* Disable both directions and reset their FIFOs */ regmap_update_bits(sai->regmap, FSL_SAI_TCSR, - FSL_SAI_CSR_TERE | FSL_SAI_CSR_FR, - FSL_SAI_CSR_FR); + FSL_SAI_CSR_TERE, 0); regmap_update_bits(sai->regmap, FSL_SAI_RCSR, - FSL_SAI_CSR_TERE | FSL_SAI_CSR_FR, - FSL_SAI_CSR_FR); + FSL_SAI_CSR_TERE, 0); + + /* TERE will remain set till the end of current frame */ + do { + udelay(10); + regmap_read(sai->regmap, FSL_SAI_xCSR(tx), &xcsr); + } while (--count && xcsr & FSL_SAI_CSR_TERE); + + regmap_update_bits(sai->regmap, FSL_SAI_TCSR, + FSL_SAI_CSR_FR, FSL_SAI_CSR_FR); + regmap_update_bits(sai->regmap, FSL_SAI_RCSR, + FSL_SAI_CSR_FR, FSL_SAI_CSR_FR); } break; default: