(In reply to Laurent Pointecouteau from comment #10)
> (In reply to Alex Deucher from comment #9)
> > Please try the patch in comment 1.
> 
> I've applied the patch and there are no more amdgpu related errors showing
> up in dmesg after booting. However, this has not fixed my dual-screen
> issues; my HDMI TV displays "no signal" after booting while plugged in my
> computer, and when trying to switch display modes using the GNOME control
> center, my DVI screen tends to get disabled and display "no signal" too,
> forcing me to hard reboot. As far as I can tell, this is the same behavior
> than before using the patched kernel. So, my issues may not be related to
> this bug ticket after all.

Please file a different bug for the display issue.