[Mesa-dev] [PATCH v2] gbm: add support for loading third-party backend (v2)

[Emil Velikov]

On 14 April 2017 at 10:38, Yu, Qiang <Qiang.Yu at amd.com> wrote:
>
> Hi Emil,
>
>> What happened with the idea of reusing your existing amdgpu_dri.so ?
>> As mentioned before the DRI loader (libgbm) <> DRI driver (foo_dri.so)
>> interface is stable, so things should just work.
> Sorry for the late reply. I've asked our amdgpu_dri.so team for this, they
> seems have no interest and resource for implementing this interface.
> So the only option left for me is to reuse our current gbm_amdgpu.so
> and upstream libgbm.so changes if possible.
>
Quick look through `strings amdgpu_dri.so' shows that you guys are
missing the DRI2_FENCE and DRI2_INTEROP extensions.
Both of which are fairly trivial to implement and it will be the better option.

Doing so will give you:
 - acknowledgement to the good work done by Marek (your colleague from
the other end of the org chart)
 - less binaries to manage - remove gbm_amdgpu.so
 - less code to manage - remove many of the libEGL and libgbm patches
that you have on top of Mesa.

The proposed GBM interface end up broken rather often since:
 - there's no open-source users that people test
 - we have no tests to catch regressions :-\

TL;DR; You really want to implement the missing functionality in
amdgpu_dri.so - its more robust and it will reduce the code you have
to maintain.

Regards,
Emil