[alsa-devel] Pops, Clicks on Capture w/ S/PDIF, Cirrus Logic CS4207, HDA

Clemens Ladisch clemens at ladisch.de
Thu Aug 12 08:54:35 CEST 2010

Dave Zielinski wrote:
> ...
> So now we're getting some audio but it comes with pops and clicks when
> we try to capture.  An analysis of the captured stream shows there are
> corruptions of the data that are 8192 frames apart which I believe are
> the 4096 frame period boundaries (although tough to know for sure).
> When the corruption occurs there seems to be 5 to 7 frames that are
> screwed up.   Also worth noting: these same exact samples appear in
> the stream at a prior location so I think its old buffer data.

How far away is that prior location; exactly buffer_size?

If not, this looks like a bug in the CS4207's RX sample rate converter.
Try disabling it by setting bit 6 in the S/PDIF interface control
register (insert "coef |= 0x0040;" in the init_digital function).


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