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

Pavel Machek
2015-05-30T10:14:41Z

On Fri 2015-05-29 22:03:06, Maxime Ripard wrote:
> On Fri, May 29, 2015 at 02:49:55PM -0500, 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:
> >
> > $ git describe a38cfebb56898633687ab337fd53710e63a0aedd
> > v3.15-rc5-72-ga38cfebb5689
> >
> > So, because this has been wrongly documented for so long, we should
> > support both bindings. Sure, deprecate touchscreen-max-[xy], but they
> > must still be supported, IMO.
>
> This property has never been anything but a typo in a documentation of
> a single driver.
>
> Feel free to fix that in that driver, but I don't see why the core
> code should handle that isolated typo.

Well... the driver was not broken... before you did "cleanup" that did
two functional changes. And yes, the dts should be fixed, but that
does not make your "cleanup" good.

Pavel
--
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