[Mesa-dev] [RFC] egl: stop claiming support for pbuffer + msaa (RFC)

[Marek Olšák]

On Thu, Sep 29, 2016 at 6:23 PM, Emil Velikov <emil.l.velikov at gmail.com> wrote:
> On 27 September 2016 at 13:47, Marek Olšák <maraeo at gmail.com> wrote:
>> On Tue, Sep 27, 2016 at 2:34 PM, Emil Velikov <emil.l.velikov at gmail.com> wrote:
>>> On 26 September 2016 at 08:41, Tapani Pälli <tapani.palli at intel.com> wrote:
>>>> This fixes a crash in egl-create-msaa-pbuffer-surface Piglit test
>>>> and same crash in many dEQP EGL tests.
>>>>
>>>> I also found that some Qt example did a workaround because of this
>>>> crash: https://bugreports.qt.io/browse/QTBUG-47509
>>>>
>>>> Signed-off-by: Tapani Pälli <tapani.palli at intel.com>
>>>> ---
>>>>
>>>> This is RFC as I'm not sure if we are supposed to support this. I tried
>>>> to verify overall pbuffer situation with some mesa-demos using pbuffer
>>>> but those are not working for me at all with or without my patch.
>>>>
>>>>  src/egl/main/eglconfig.c | 5 +++++
>>>>  1 file changed, 5 insertions(+)
>>>>
>>>> diff --git a/src/egl/main/eglconfig.c b/src/egl/main/eglconfig.c
>>>> index 6161d26..20cf9d4 100644
>>>> --- a/src/egl/main/eglconfig.c
>>>> +++ b/src/egl/main/eglconfig.c
>>>> @@ -407,6 +407,11 @@ _eglValidateConfig(const _EGLConfig *conf, EGLBoolean for_matching)
>>>>        return EGL_FALSE;
>>>>     }
>>>>
>>>> +   /* pbuffer with MSAA not supported */
>>> Fwiw on my system piglit also crashes + the demos don't render
>>> anything. So I'm leaning that we want this as-is (for the time being)
>>> + cc stable ?
>>>
>>> Can you apply a minor polish to the comment - "XXX/TODO: pbuffer +
>>> MSAA does not work + QT bugreport" or alike.
>>
>> Please don't add "XXX/TODO". pbuffers were spec'd in 1997 and were
>> meant to be used on GL 1.x hardware that didn't support MSAA
>> texturing, thus MSAA pbuffers don't make any sense. Just keep the
>> current comment.
>>
> Can we use your reply instead - it's wise to have the not as often
> visited parts nicely documented ?

I don't think my comment is useful if the pbuffer is not expected to
be bound as a texture. Your TODO comment is better. Sorry for the
noise.

Marek