[PATCH v2 6/6] ARM: sun8i: dts: Add Ippo-q8h v1.2 with A33 and 1024x600 lcd support

Hans de Goede
2015-06-18T20:16:25Z

Hi,

On 18-06-15 20:37, Maxime Ripard wrote:
> On Wed, Jun 17, 2015 at 09:16:02AM +0200, Hans de Goede wrote:
>> Hi,
>>
>> On 16-06-15 19:41, Maxime Ripard wrote:
>>> Hi,
>>>
>>> On Sat, Jun 13, 2015 at 04:18:59PM +0200, Hans de Goede wrote:
>>>>> Pantelis, to sum things up, we have a case of a tablet that comes with
>>>>> the exact same board, but coming in two flavours with two differents
>>>>> screen resolutions. It looks like a great case for your DT quirks
>>>>> work, but we have no way of runtime detecting the difference between
>>>>> the two variants. What do you think about this? Should we go with
>>>>> using the DT quirks or is this simply out of scope?
>>>>>
>>>>> There's not so much example of similar cases in the kernel, and none
>>>>> of them use quirks so far (obviously) but they all boil down to either
>>>>> the solution you were suggesting in that patch or adding the alternate
>>>>> configuration as a comment.
>>>>>
>>>>> I don't think the latter would work for you, and I agree with that, so
>>>>> I guess that depending on what Pantelis says, either we go with a
>>>>> better solution using the quirks, or we end up using what you
>>>>> suggested (with a nitpick though, I'd prefer if you used the display
>>>>> standard instead of the resolution, which would make it xga I guess?)
>>>>
>>>> If we go with a separate dts file for each of the 800x480 and 1024x600
>>>> screens, I would greatly prefer to stick with the lcd1024x600 in the dts
>>>> filename instead of using something like xga, the fact that you say:
>>>> "I guess" that my answer to that is: I dunno I would need to look this
>>>> up in wikipedia or some such makes me think that using a qualifier like
>>>> xga is not going the help end users decide which dts file to pick, it
>>>> will just lead to them needing to go to wikipedia too. Also note that
>>>> the advertising of these tablets on ebay / aliexpress almost always
>>>> uses the resolution and not something like "xga".
> <> >>
>>>> So all in all if we do not decide to use quirks for this I would like
>>>> to keep the filename as is.
>>>
>>> Yeah, except that the display standard is also encoding the refresh
>>> rate and color depth
>>
>> Huh? No it does not, see e.g.:
>>
>> https://en.wikipedia.org/wiki/Graphics_display_resolution
>>
>> Note nothing about depth and refresh-rate there, and I've really never
>> heard anyone use things like xga to refer to colordepth and/or refreshrate
>
> I was somehow convinced it did, and
>
> https://en.wikipedia.org/wiki/Computer_display_standard

Hmm, that is a weird page it seems to be a rather low quality page for
wikipedia standards, for some reason it throws Atari ST models in there
as being display standards, and the bpp column makes sense for hercules,
cga and ega but not much which comes after that.

Regards,

Hans