[alsa-devel] [PATCH] Change of cold reset and ac97 register cache

Robert Jarzmik rjarzmik at free.fr
Fri Jan 18 20:50:42 CET 2008

Mark Brown <broonie at opensource.wolfsonmicro.com> writes:

> Just to clarify, it is the initial reset on chip probe that is causing
> problems for you rather than a call later on?  If the driver state and
> chip state are out of sync after that then that suggests that there is
> an error in the register defaults or some other similar issue.
It's the initial on chip probe in my case.

> > After that, I need to setup a specific GPIO to trigger loud speaker
> > amplificator. The trouble is that I do not want to trigger another GPIO which
> > powers another amplificator.
> > My code basically reads de GPIO register, put the right bit, and stores back.
> > But because of cache/chip difference, I trigger the other GPIO.
> How exactly are you doing these accesses and which registers is it that
> trigger the problem - is it setting the GPIO state or configuring the
> GPIO pin modes?

I'm setting up a wm9713 GPIO (GPIO8) as input, and then set the pull-up
register to power my speaker amplification.

As we said, I'll implement a machine dependent solution, assuming there'll be in
the future a mecanism in ASoC v2 allowing hook inscription for the reset phase.
I'll synchronize the cache in this specific function, and will wait ASoC to
catch up or propose a patch.


PS: Sorry for the list, in my last reply I forgot alsa-devel.

More information about the Alsa-devel mailing list