Created attachment 135751 [details]
dmesg with amdgpu.dc=1

I have a Dell U2713HM connected to a Radeon RX470 (MSI board, 'Radeon RX470
Gaming 4G') over dual-link DVI on Linux 4.15-rc1. When enabling DC (Kernel
commandline amdgpu.dc=1), the monitors native resolution of 2560x1440 is not
detected, when falling back to default modesetting, everything works fine.
Xorg.log and (relevant parts) of dmesg for both amdgpu.dc=1 and =0 are
attached.