glamor woes with nouveau

[Olivier Fourdan]

Hi Eric

On 17 January 2017 at 21:25, Eric Anholt <eric at anholt.net> wrote:
>
> It sounds like nouveau is failing at the getteximage/texsubimage cycle
> in the fallback path.  X sometimes finds bugs in Mesa than our testcases
> miss, because it frequently reads/writes subsets of a texture.  In
> comparison, testcases tend to use solid colors, window system
> renderbuffers instead of textures, and the whole renderbuffer instead of
> a subset.
>
> I'd recommend getting an apitrace of the rendering under Xephyr -glamor,
> if possible.   Then you can use apitrace to dump images of each draw
> call on both intel and nouveau, and identify which draw call/texture
> upload was the one that failed.

This is where it gets even more confusing, I cannot reproduce the
issue using "Xephyr -glamor"...  Not even with Xephyr running in
Xwayland.

I can reproduce on Xwayland though (I mean, running another Xwayland
server in a Wayland session), I can capture an apitrace of that, but
the apitrace looks incomplete and cannot be replayed (no context).

Cheers,
Olivier