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ASoC: fsl_sai: Fix noise when using EDMA

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EDMA requires the period size to be multiple of maxburst. Otherwise the
remaining bytes are not transferred and thus noise is produced.

We can handle this issue by adding a constraint on
SNDRV_PCM_HW_PARAM_PERIOD_SIZE to be multiple of tx/rx maxburst value.

Signed-off-by: Mihai Serban <mihai.serban@nxp.com>
Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
Acked-by: Nicolin Chen <nicoleotsuka@gmail.com>
Link: https://lore.kernel.org/r/20190913192807.8423-2-daniel.baluta@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Mihai Serban 2019-09-13 22:28:05 +03:00 committed by Mark Brown
parent fca11622d6
commit e75f4940e8
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
2 changed files with 16 additions and 0 deletions
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15
sound/soc/fsl/fsl_sai.c
View File

@ -628,6 +628,16 @@ static int fsl_sai_startup(struct snd_pcm_substream *substream,
FSL_SAI_CR3_TRCE_MASK,
FSL_SAI_CR3_TRCE);
/*
* EDMA controller needs period size to be a multiple of
* tx/rx maxburst
*/
if (sai->soc_data->use_edma)
snd_pcm_hw_constraint_step(substream->runtime, 0,
SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
tx ? sai->dma_params_tx.maxburst :
sai->dma_params_rx.maxburst);
ret = snd_pcm_hw_constraint_list(substream->runtime, 0,
SNDRV_PCM_HW_PARAM_RATE, &fsl_sai_rate_constraints);
@ -1026,30 +1036,35 @@ static int fsl_sai_remove(struct platform_device *pdev)
static const struct fsl_sai_soc_data fsl_sai_vf610_data = {
.use_imx_pcm = false,
.use_edma = false,
.fifo_depth = 32,
.reg_offset = 0,
};
static const struct fsl_sai_soc_data fsl_sai_imx6sx_data = {
.use_imx_pcm = true,
.use_edma = false,
.fifo_depth = 32,
.reg_offset = 0,
};
static const struct fsl_sai_soc_data fsl_sai_imx7ulp_data = {
.use_imx_pcm = true,
.use_edma = false,
.fifo_depth = 16,
.reg_offset = 8,
};
static const struct fsl_sai_soc_data fsl_sai_imx8mq_data = {
.use_imx_pcm = true,
.use_edma = false,
.fifo_depth = 128,
.reg_offset = 8,
};
static const struct fsl_sai_soc_data fsl_sai_imx8qm_data = {
.use_imx_pcm = true,
.use_edma = true,
.fifo_depth = 64,
.reg_offset = 0,
};

1
sound/soc/fsl/fsl_sai.h
View File

@ -157,6 +157,7 @@
struct fsl_sai_soc_data {
bool use_imx_pcm;
bool use_edma;
unsigned int fifo_depth;
unsigned int reg_offset;
};