https://bugs.freedesktop.org/show_bug.cgi?id=60879
--- Comment #17 from Alex Deucher agd5f@yahoo.com --- (In reply to comment #16)
Created attachment 76921 [details] Screenshots with and without glamor
X11 doesn't render properly. The pixels seem to be shuffled. Maybe a shader doesn't write where it's supposed to?
Looks like the tiling configuration is wrong on your system.