[alsa-devel] SoC pxa2xx-ac97 + wm9705 + touchscreen suspend/resume

Russell King - ARM Linux linux at arm.linux.org.uk
Thu Apr 2 13:55:41 CEST 2009

On Tue, Mar 31, 2009 at 08:15:40PM +0100, Mark Brown wrote:
> On Tue, Mar 31, 2009 at 07:37:55PM +0100, Russell King - ARM Linux wrote:
> > I don't think this is the complete story.  Sometime between 2.6.27 and
> > 2.6.29, the structure below /sys/devices/platform/soc-audio changed
> > (the ac97 codec moved to the top level.)
> Oh, are you using the ac97.c codec driver?

No, I'm using the wm9705 driver.

> With a normal ASoC codec
> driver the AC97 codec is not visible as a separate device in the device
> tree - if you could point me to your machine driver that'd be helpful.

Not true - the codec appears as /sys/devices/0-0:WM9705 rather than a
sub-device of the AC97 controller.  Below this there are two sub-devices:


The wm97xx-ts touchscreen driver binds to the 0-0:WM9705 device, so
clearly unless 0-0:WM9705 is a child of the AC97 controller, things
aren't going to be guaranteed to be resumed in the right order.

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