https://bugs.freedesktop.org/show_bug.cgi?id=103791
--- Comment #13 from Michel Dänzer michel@daenzer.net --- Created attachment 135923 --> https://bugs.freedesktop.org/attachment.cgi?id=135923&action=edit drm_vblank_get debugging output
Please do the same with this patch, to see why drm_vblank_get returns -EINVAL.