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

[Tomi Valkeinen <tomi.valkeinen@ti.com>]

On 12/12/2019 22:35, Laurent Pinchart wrote:
> 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@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 ?

Hmm, I just realized that changing these will break omapfb. It relies on panel-dpi and timings from 
DT...

  Tomi

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