[alsa-devel] [PATCH 0/2] ASoC: tlv320dac33 fixes

Jarkko Nikula jhnikula at gmail.com
Thu Mar 11 16:07:38 CET 2010

On Thu, 11 Mar 2010 16:55:12 +0200
Peter Ujfalusi <peter.ujfalusi at nokia.com> wrote:

> > Just curious: what would happen if the BCLK is cut while the McBSP is
> > operating?
> The symptom is that we can not access to McBSP register address space causing 
> kernel panic, which can only be fixed by rebooting the device.
> The burst driven BCLK causes some internal state machine to stuck, leaving the 
> given McBSP port dead from the outside. Other ports operate after this event.
> Obviously this only bites in McBSP slave mode, and with codec like DAC33 which 
> have burst mode, in other cases the BCLK is always running (or McBSP is master).
> > I'm thinking are there also other similar problems, e.g. if
> > the rate is not correct.
> Hmmm, could be possible, but I did not experienced with such a problem.
Thanks for sharing this info.

Sounds exactly similar problem what I encountered once with the OMAP2420
and EAC. I didn't debug that problem any further then but there also
some register accesses (not all) caused kernel panic if the external
clock was missing or if the rate wasn't correct.


More information about the Alsa-devel mailing list