[Acked] [Quantal SRU][PULL] fix XPS12 Cypress PS/2 trackpad

[Andy Whitcroft]

On Wed, Apr 03, 2013 at 02:06:21PM -0700, Kamal Mostafa wrote:
> Bug reference:
> 
> 	https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1103594
> 	Cypress Trackpad mis-detected as "PS/2 Cypress Trackpad" on XPS 12
> 
> [IMPACT]
> 
> Due to a firmware change in the Cypress PS/2 trackpad, the driver fails
> to properly detect the trackpad in the Dell XPS12 and possibly other models,
> leaving the trackpad dysfunctional.
> 
> This patch -- a trivial backport from upstream -- fixes the detection glitch
> in the driver.  The patch was cherry-picked into Raring.
> 
> [TESTCASE]
> 
> The patch was deployed as SAUCE in Raring some weeks ago, as well as in the
> Sputnik kernel PPA for Q and P.  It has been verified to fix the problem in
> all three.
> 
> [Regression Potential]
> 
> Low potential for regression: The change will only affect Cypress PS/2
> trackpads (the problem and fix occur only after the trackpad has already been
> detected as a Cypress), and it has been reasonably widely tested on Cypress
> pads with the older firmware via the Sputnik PPA.
> 
> Thanks,
> 
>  -Kamal

Looks to be self contained and specific to a version of one piece of
hardware.  Appears reasonably well tested.

Acked-by: Andy Whitcroft <apw at canonical.com>

-apw