https://bugzilla.kernel.org/show_bug.cgi?id=199319
--- Comment #14 from haro41@gmx.de --- linux 4.16.1, R9 380X, Mesa 18.1.0-devel (git-d899826733), X11(1.19.6)
with:
amdgpu.dc=0: no flickering, HDMI audio works
amdgpu.dc=1: flickering, HDMI audio not working