[Mesa-dev] [PATCH 0/3] Support for Android RGBX/RGBA formats

[Marek Olšák]

On Sun, Apr 24, 2016 at 3:09 PM, Marek Olšák <maraeo at gmail.com> wrote:
> On Sun, Apr 24, 2016 at 2:16 PM, Marek Olšák <maraeo at gmail.com> wrote:
>> On Fri, Apr 22, 2016 at 12:41 PM, Chih-Wei Huang
>> <cwhuang at android-x86.org> wrote:
>>> 2016-04-21 21:42 GMT+08:00 Emil Velikov <emil.l.velikov at gmail.com>:
>>>>
>>>> On 19 April 2016 at 20:38, Rob Herring <robh at kernel.org> wrote:
>>>>> The RGBX/RGBA pixel formats used in the Android EGL don't get configs
>>>>> created due to the missing formats in the DRI state tracker. This series
>>>>> adds the necessary formats for configs and DRI images. Support in GBM is
>>>>> also added as it will be needed soon for Android.
>>>>>
>>>>> AFAICT, this has been a long standing bug in Android-x86 which was
>>>>> worked around with the patch "GLSurfaceView: Be less picky about
>>>>> EGLConfig alpha sizes". With this series, this patch is no longer needed
>>>>> and several other bugs like wallpaper not getting displayed are fixed.
>>>>>
>>>> In the past similar changes has caused unexpected bugs and/or pert regressions.
>>>>
>>>> Although I doubt we'll notice them with the patches on the ML, thus
>>>> I've pushed the lot to get some wider testing.
>>>>  Please keep an eye for fires ;-)
>>>
>>> Could these be back-ported to 11.2?
>>
>> DEFINITELY NOT.
>>
>> It's too risky and it has already broken GLX.
>
> OK so the problem is libGL ignores the red/green/blue mask, therefore
> it doesn't distinguish between BGRA and RGBA. Also, DRI always assumes
> it's BGRA on the X server side. This patch series also ignores the
> red/green/blue mask for imported buffers. That's why DRI2 mostly
> works. I haven't tested DRI3.
>
> libGL could be fixed not to expose RGBA visuals, but that's
> insufficient, because Mesa drivers must be loadable by older libGL
> too.
>
> The bottom line is st/dri can't expose RGBA, because it would break
> Mesa with old libGL.
>
> Unless you guys come up with a solution, I'll have to revert the st/dri change.

FYI, I've decided to revert the st/dri commit now to fix the KDE
issue.

Marek