[Mesa-dev] [PATCH 4/4] egl/dri2: add image extension to swrast_core_extensions

[Emil Velikov]

On 19 June 2017 at 20:46, Chad Versace <chadversary at chromium.org> wrote:
> On Thu 15 Jun 2017, Gurchetan Singh wrote:
>> Emil, would you be fine with leaving the image extension in dri2.c but still
>> adding it as a drisw extension?  That solution would look like:
>>
>> [1]https://patchwork.freedesktop.org/patch/154807/
>
> Observations:
>     - src/gallium/state_trackers/dri/dri2.c:dri2ImageExtension advertises v15 of __DRI_IMAGE.
>     - egl_dri2.c requires only v1 of __DRI_IMAGE. Maybe a higher version
>       is required in practive, but the egl_dri2.c code checks only for v1.
>
> Questions:
>     1. All functions implemented in dri2.c:dri2ImageExtensions, do they
>        under swrast? Honest question, because I'm no expert on
>        gallium.
>
> If question #1 is true, then I see no problem with your latest plan. But
> maybe Emil does.
>
> If question #1 is false, it should be straightforward to implement in
> drisw.c the small subset of __DRI_IMAGE functions required for v1.

While I haven't checked how much [or well] DRI_IMAGE works with
swrast, there's no need to actually add it there.
An alternative is to add kms_swrast support for EGL like we already do
for GBM, as mentioned earlier [1].

Gents, keep in mind that:
 - one cannot pull DRM specifics (dri2.c) code within drisw.c, and
 - DRI_IMAGE pulls DRM specifics, hence adding it into drisw.c is
again a no-go :-\

FWIW the above architectural split applies for classic drivers as
well. swrast_dri.so simply cannot depend on anything DRM related.

-Emil

[1] https://lists.freedesktop.org/archives/mesa-dev/2017-June/159519.html