https://bugs.freedesktop.org/show_bug.cgi?id=94860
--- Comment #6 from lumks@ymail.com --- (In reply to Michel Dänzer from comment #5)
Setting the environment variable R600_DEBUG=nodcc for the kwin process works around this problem for me.
+1 it also worksaround wayland session and maybe also this one: https://bugs.kde.org/show_bug.cgi?id=361154 (i dont know right now for sure but it looks like it does)