[alsa-devel] [PATCH 1/2] ASoC: omap-mcbsp: Correct the DSP_B mode

Jarkko Nikula jarkko.nikula at nokia.com
Tue Apr 14 10:20:16 CEST 2009


On Tue, 14 Apr 2009 09:45:30 +0200
"Ujfalusi Peter (Nokia-D/Tampere)" <peter.ujfalusi at nokia.com> wrote:

> Use correct DSP_B mode configuration for omap-mcbsp.
> 
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi at nokia.com>
> ---
>  sound/soc/omap/omap-mcbsp.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/sound/soc/omap/omap-mcbsp.c b/sound/soc/omap/omap-mcbsp.c
> index 9c09b94..4440bab 100644
> --- a/sound/soc/omap/omap-mcbsp.c
> +++ b/sound/soc/omap/omap-mcbsp.c
> @@ -283,7 +283,7 @@ static int omap_mcbsp_dai_hw_params(struct
> snd_pcm_substream *substream, break;
>  	case SND_SOC_DAIFMT_DSP_B:
>  		regs->srgr2	|= FPER(wlen * channels - 1);
> -		regs->srgr1	|= FWID(wlen * channels - 2);
> +		regs->srgr1	|= FWID(0);
>  		break;
>  	}

Grr, I have some practical problems with my Beagle refusing to mount my
SD card root but I give a test when I get it working.

But I fear this change makes it into DSP_B with inverted FS polarity.
Register srgr1 defines the FS length and it's active low. I think this
will be correct if you switch the polarity in
omap_mcbsp_dai_set_dai_fmt.

At least defining pulse witdth with FWID(0) is more clear than FWID
(wlen * channels - 2) :-)


Jarkko


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