Created attachment 189561 [details] Xorg log of 4.3.rc3 Lengthy explanation posted here: https://forums.gentoo.org/viewtopic-p-7824374.html Dual Monitor setup doesn't seem to work at all when both are connected via DVI. When one is connected to HDMI and the other to the first DVI, dual monitor only works when one of them is connected after boot. Both only work when one is connected to HDMI and the other to the second DVI. With neither configuration does rotating any screen work. Results in crash of the X server (attachment). Everything works as intended under Windows. What I mean with "dual monitor is not working" is that both screens are recognized as connected but one of the screens shows only a black picture, but I can move applications to it (which I can't see). Steps to reproduce: Boot computer and try to rotate one of the screens with the KDE system settings or xrandr.
Created attachment 189571 [details] dmesg
FWIW, rotation doesn't work because glamor fails to initialize, so all hardware acceleration is disabled (I posted a xf86-video-amdgpu patch to not advertise rotation capability in this case). Looks like Mesa is either misconfigured or too old for your card.
(In reply to Michel Dänzer from comment #2) > FWIW, rotation doesn't work because glamor fails to initialize, so all > hardware acceleration is disabled (I posted a xf86-video-amdgpu patch to not > advertise rotation capability in this case). Looks like Mesa is either > misconfigured or too old for your card. Thank you very much, I didn't notice that. I searched for that problem and tried glxinfo which told me, that llvm version 3.6.1 was required, which I didn't know. So after installing it, the server doesn't crash anymore upon trying to rotate the screen and it finally works. It's probably still a bug that the monitors only work with the second DVI slot and one in HDMI, but this works for me as well. I'm not sure if I'd call it "resolved" but for me it's at least "workaround is now good enough"
Please try to reproduce this bug with latest kernel image.