Re: [PATCH] fix n900 dts file to work around 4.1 touchscreen regression on n900

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Fri, May 29, 2015 at 09:56:29PM +0200, Pavel Machek wrote:
> On Fri 2015-05-29 14:49:55, Felipe Balbi wrote:
> > Hi,
> > 
> > On Fri, May 29, 2015 at 09:32:11PM +0200, Pavel Machek wrote:
> > > Fix dts to match what the Linux kernel expects. This works around
> > > touchscreen problems in 4.1 linux on Nokia n900.
> > >     
> > > Signed-off-by: Pavel Machek <pavel@ucw.cz>
> > > 
> > > diff --git a/Documentation/devicetree/bindings/input/touchscreen/tsc2005.txt b/Documentation/devicetree/bindings/input/touchscreen/tsc2005.txt
> > > index 4b641c7..09089a6 100644
> > > --- a/Documentation/devicetree/bindings/input/touchscreen/tsc2005.txt
> > > +++ b/Documentation/devicetree/bindings/input/touchscreen/tsc2005.txt
> > > @@ -32,8 +32,8 @@ Example:
> > >  		touchscreen-fuzz-x = <4>;
> > >  		touchscreen-fuzz-y = <7>;
> > >  		touchscreen-fuzz-pressure = <2>;
> > > -		touchscreen-max-x = <4096>;
> > > -		touchscreen-max-y = <4096>;
> > > +		touchscreen-size-x = <4096>;
> > > +		touchscreen-size-y = <4096>;
> > 
> > IMHO, the older binding needs to be supported as well. It's fine to
> > update the DTS for the new binding, but even Documentation says
> > touchscreen-max-[xy] and if the driver changed that, the driver should
> > be fixed too. Besides, it seems like this has been in tree since
> > v3.16:
> 
> Agreed. In parent email, I have list of two commits that should be
> reverted.

Well, not exactly. The kernel has never parsed touchscreen-max-x and
touchscreen-max-y, however we did indeed change behavior of
touchscreen_parse_of_params() to reset both max and fuzz if either one is
present... I guess we can adjust the behavior it for the sake of tsc2005.

-- 
Dmitry