[alsa-devel] [PATCH] ASoC: fsl-ssi: Fix bitclock calculation for master mode

Nicolin Chen nicoleotsuka at gmail.com
Fri Jul 3 10:44:05 PDT 2015


On Fri, Jul 03, 2015 at 12:39:36PM +0200, Juergen Borleis wrote:
> According to the datasheet 'pm', 'psr' and 'div2' should never be all 0.
> Since commit 541b03ad6cfe ("ASoC: fsl_ssi: Fix the incorrect limitation of
> the bit clock rate") this can happen, because for some bitclock rates
> 'pm' = 0 seems to be a valid choice but does not work due to hardware
> restrictions. This results into a bad hardware behaviour (slow audio for
> example). Feature tested on a i.MX25.
> 
> Signed-off-by: Juergen Borleis <jbe at pengutronix.de>

Acked-by: Nicolin Chen <nicoleotsuka at gmail.com>

Thank you!

> ---
>  sound/soc/fsl/fsl_ssi.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
> index c7647e0..c0b940e 100644
> --- a/sound/soc/fsl/fsl_ssi.c
> +++ b/sound/soc/fsl/fsl_ssi.c
> @@ -633,7 +633,7 @@ static int fsl_ssi_set_bclk(struct snd_pcm_substream *substream,
>  		sub *= 100000;
>  		do_div(sub, freq);
>  
> -		if (sub < savesub) {
> +		if (sub < savesub && !(i == 0 && psr == 0 && div2 == 0)) {
>  			baudrate = tmprate;
>  			savesub = sub;
>  			pm = i;
> -- 
> 2.1.4
> 
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