[alsa-devel] [PATCH 2/2] Add possibility to control the GPIO_STATUS shift

Mark Brown broonie at opensource.wolfsonmicro.com
Fri Jul 17 12:32:53 CEST 2009

On Fri, Jul 17, 2009 at 10:01:16AM +0200, Marek Vasut wrote:

> This patch allows tweaking the behaviour of GPIO_STATUS register
> shift quirk that's in wm97xx-core. The problem with GPIO_STATUS 
> register being shifted by one doesn't appear on all hardware it 
> seems and causes problems with accelerated touchscreen drivers on
> Palm hardware. Therefore an accelerated touchscreen driver can select
> if the shift is/isn't happening on the hardware.                     

Again, this isn't an ALSA patch.

I've done some checking internally and I'm very suspicous that what's
going on here is actually the masking of some other bug elsewhere in the
system.  Which CPU are the systems you're observing this on using?
There is at least one special case in the current code for GPIO register
readbacks in the PXA AC97 driver code and there have been a number of
interoperabilty issues in that area...

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