https://bugs.freedesktop.org/show_bug.cgi?id=102507
--- Comment #3 from Dieter Nützel Dieter@nuetzel-hh.de --- (In reply to Vedran Miletić from comment #2)
Found it: https://lists.freedesktop.org/archives/amd-gfx/2017-August/012283.html
Guess I should subscribe to one more list. :-)
Maybe or I _should_ make better bug reports in the beginning...;-)
Greetings, Dieter