https://bugs.freedesktop.org/show_bug.cgi?id=89015
--- Comment #13 from smoki smoki00790@gmail.com ---
modesetting in dri2 mode is fine here :). Probably, but do you use xserver's modesetting driver in dri3 mode?
There are whole bunch of piglit crashes and gpu lockups here with anything dri3 related - be it with xserver's modeseting or radeon ddx (i tried this patched radeon https://github.com/iXit/xf86-video-ati/commits/master and it suffer from the same issues like modesetting)