Comment # 62 on bug 110214 from Diego Viola

We found quite a few things during our research:

export MESA_EXTENSION_OVERRIDE="-GL_NV_texture_barrier"

This helps alleviate the problem (xterm does not have the issue with this),
however, the problem is still present in Xephyr.

We tested Xephyr from the current git master down to Xephyr from xserver 1.16
and the problem is also present, however, setting the following environment
variable:

export R600_DEBUG=nodpbb

Makes the issue disappear entirely.