[alsa-devel] AC97 reset fail after suspend

Marek Vasut marek.vasut at gmail.com
Thu May 14 15:51:37 CEST 2009

On Thursday 14 of May 2009 14:32:41 Mark Brown wrote:
> On Thu, May 14, 2009 at 03:57:35AM +0200, Marek Vasut wrote:
> > The following patch fixes the issue and should be correct. It's indeed a
> > regression that's not in wm9713, but is in wm9712. Please consider
> > applying.
> Please CC maintainers on patches!

Sorry, it was 4am when I sent this patch, I was a little tired.
> > The following patch fixes problem with wm9712 codec being unable to
> > resume from sleep because it doesn't respond after AC97 port was
> > coldreseted (which is done in case the warmreset wasn't successful). The
> > solution uses similar approach as wm9713, that is, do one more warmreset
> > after coldreset.
> Are you sure this is required?  The WM9713 needs this because the
> default state on reset is not to clock the AC97 link, a warm reset is
> needed to start the link.  I'll need to check but IIRC the WM9712 runs
> the link by default and I can't see any changes to this behaviour in the
> driver changelog.

Well without this, the codec doesn't kick in (reading the registers returns 
all zeros) so I assume that's the same issue as on wm9713.

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