[alsa-devel] [PATCH] ASoC: fsl_esai: Clear the xPM bit when using xFP

[Marek Vasut]

On 04/08/2018 03:14 AM, Nicolin Chen wrote:
> On Sat, Apr 07, 2018 at 03:02:21PM +0200, Marek Vasut wrote:
>> When setting xFP directly, set the xPM predivider to 1, otherwise
>> it could remain set to previously set incorrect value and interfere
>> with the correct clocking.
> 
> This doesn't sound right to me.

OK

> Could you please provide a failed
> instance? It's been a while since I wrote the code. But I can tell
> that PM is supposed to be called by set_sysclk() only, while FP is
> used for bclk. If you clear PM when setting FP, the output of HCK
> could be messed.

Try feeding it the following values, The codec I use is PCM1808.

fsl_esai_set_dai_sysclk[227] clk_id=0 freq=24576000 dir=1
fsl_esai_divisor_cal[131] tx=0 ratio=2 usefp=0 fp=0
fsl_esai_set_bclk[322] tx=0 freq=3072000
fsl_esai_divisor_cal[131] tx=0 ratio=8 usefp=1 fp=8

Also, I think there is another bug in the fsl_esai_divisor_cal() now
that I look at it. If usefp = 0, then maxfp = 1 , then savesub = 0 and
then in the loop sub is never < savesub , although the loop will
terminate on savesub == 0 immediately with pm = 999 and the driver will
fail.

> Thanks
> Nicolin
> 
>> Signed-off-by: Marek Vasut <marex at denx.de>
>> Cc: Fabio Estevam <fabio.estevam at nxp.com>
>> Cc: Gustavo A. R. Silva <garsilva at embeddedor.com>
>> Cc: Mark Brown <broonie at kernel.org>
>> ---
>>  sound/soc/fsl/fsl_esai.c | 5 ++++-
>>  1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/sound/soc/fsl/fsl_esai.c b/sound/soc/fsl/fsl_esai.c
>> index 40a700493f4c..9f69823b50d7 100644
>> --- a/sound/soc/fsl/fsl_esai.c
>> +++ b/sound/soc/fsl/fsl_esai.c
>> @@ -128,8 +128,11 @@ static int fsl_esai_divisor_cal(struct snd_soc_dai *dai, bool tx, u32 ratio,
>>  
>>  	maxfp = usefp ? 16 : 1;
>>  
>> -	if (usefp && fp)
>> +	if (usefp && fp) {
>> +		regmap_update_bits(esai_priv->regmap, REG_ESAI_xCCR(tx),
>> +				   ESAI_xCCR_xPM_MASK, 0);
>>  		goto out_fp;
>> +	}
>>  
>>  	if (ratio > 2 * 8 * 256 * maxfp || ratio < 2) {
>>  		dev_err(dai->dev, "the ratio is out of range (2 ~ %d)\n",
>> -- 
>> 2.16.2
>>
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-- 
Best regards,
Marek Vasut