[igt-dev] [PATCH] tests/kms_cursor_legacy: Fix assertion failure due to vblank mismatch

[Chris Wilson]

Quoting Maarten Lankhorst (2019-03-20 15:44:36)
> Op 13-03-2019 om 21:41 schreef Chris Wilson:
> > Quoting Nischala Yelchuri (2019-03-13 20:16:35)
> >> For the !modeset case, after a pageflip is performed on both crtc's,
> >> vblank counter is advanced by 1 when compared to its original value.
> >>
> >> For the modeset case, when pageflips and modesets are interleaved,
> >> vblank counter does not always advance by 1 as nonblocking modeset
> >> could fail, in which case we do not need vblank_matches.
> > Having acknowledged the bug, try fixing it.
> > -Chris
> > _______________________________________________
> > igt-dev mailing list
> > igt-dev at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/igt-dev
> 
> Hey,
> 
> Not sure that's possible. We need access to all crtc_state's when reallocating ddb, and this means a pageflip on the first crtc is stalled while doing a modeset on another.
> 
> The page flip will be blocked on the nonblocking modeset to complete.

And it should still only take a vblank... Right? (That is what the test
is complaining about that it takes more than a vblank to update iirc.)

But I'll leave it in your hands if you think the test is too demanding,
you came up with it after all :)
-Chris