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

[Jarkko Nikula]

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.


-- 
Jarkko