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

Jarkko Nikula jarkko.nikula at nokia.com
Tue Apr 14 11:02:21 CEST 2009

On Tue, 14 Apr 2009 10:40:16 +0200
"Ujfalusi Peter (Nokia-D/Tampere)" <peter.ujfalusi at nokia.com> wrote:

> > 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.
> As I written in the introduction mail, one has to verify and pick the
> correct pair of DSP_A/_B mode and FS/clock polarity in order to have
> correct config... I think it is acceptable to assume, that whoever
> writes such a board file should have at least this level of
> understanding of the FS/bitclock and how the data is driven and how
> the data is sampled.
The pairs must mach. It's clearly a bug if another end is have to set
different polarity than another. Those polarity defines are with
respect to the mode, not e.g. what's the McBSP default.


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