Comment # 6 on bug 73946 from Michel Dänzer

This is probably because the Gallium textures which end up being scanned out
are created without the PIPE_BIND_SCANOUT flag set, so they end up with a
tiling mode which is not supported by the display engine. I can reproduce
similar issues with weston, especially when making apps fullscreen, and I can
work around it in the radeonsi driver by always creating textures as if the
PIPE_BIND_SCANOUT flag was set.