HW setup: RX580, i7 4770, intel board h87rl.
SW setup: Ubuntu 18.04, amdgpu pro 18.20-606296 driver.
Setup works perfectly fine with a NEC EA244WMi (1980x1200 via HDMI).
On my AOC 3277 (4k via HDMI 2.0) I get a blank screen, allways.
The setup kind of works if I set 'nomodeset' and start X11 by hand. But when doing this, DRI won't function properly.
Looking at Xorg.0.log, the proper modes seem to be identified.
But dmesg.log shows this line:
[drm] dce_get_required_clocks_state: clocks unsupported disp_clk 709776 pix_clk 533250
Modesetting / EDID problem?
Setup works on windows 10 with latest AMD driver. (and with a 950GTX with proprietary NV driver)
Tried a different HDMI cable, to no avail.