[PATCH 2/3] ARM: dts: am437x-gp/epos-evm: drop unused panel timings

[Laurent Pinchart]

Hi Tomi,

On Thu, Dec 12, 2019 at 11:37:51AM +0200, Tomi Valkeinen wrote:
> On 11/12/2019 18:53, Tony Lindgren wrote:
> > * Laurent Pinchart <laurent.pinchart at ideasonboard.com> [191202 13:05]:
> >> Hi Tomi,
> >>
> >> Thank you for the patch.
> >>
> >> On Thu, Nov 14, 2019 at 11:39:49AM +0200, Tomi Valkeinen wrote:
> >>> panel-simple now handled panel osd070t1718-19ts, and we no longer need
> >>> the panel timings in the DT file. So remove them.
> >>
> >> Should you in that case drop the panel-dpi compatible string too, as the
> >> panel-dpi bindings require panel timings in DT ?
> > 
> > Yeah sounds like if panel-dpi is no longer usable for this device it
> > should be dropped from the compatible list.
> 
> Ok, I agree.
> 
> Looking at the dts files, panel-dpi is used in a bunch of boards. But
> we even have 3 dts files with panel-dpi, without the detailed panel
> model in compatible...
> 
> Fixing those will break the compatibility with old dtbs and new
> kernel, unless we add timings-from-dt to a panel driver that handles
> panel-dpi.

I know, and I don't have a perfect answer for this :-( I don't see a
third option, it's either breaking DT backward compatibility or adding
timings parsing to a panel driver (either a new panel-dpi driver or to
panel-simple). What's your preferred option ?

-- 
Regards,

Laurent Pinchart