So this is regarding AMDGPU DAL as it currently exists in
https://cgit.freedesktop.org/~agd5f/linux/log/?h=amd-staging-4.7, which from my
understanding contains the most up-to-date public-facing iteration of the DAL
patch.

So I have an HDMI 2.0 4K 60 Hz monitor (Vizio D40u-D1) as my main display
connected to an XFX RX 480. I'm using a kernel compiled from the branch listed
above.

Now the issue I'm having is that I'm stuck at 30 Hz. The RX 480 is capable of
driving this monitor at 60 Hz @ 4K, which works under Windows. Trying to switch
to 60 Hz either results in no signal, or just 30 Hz again.

I had the same issue in the past with the proprietary Linux Nvidia drivers on a
960 GTX I used to own, and after several months, the devs there were able to
figure out what the issue is, describe it in a forum post, and get a fix in.
See here:
https://devtalk.nvidia.com/default/topic/939971/linux/4k-60hz-works-in-windows-not-in-linux/

So what I'm hoping is that a similar fix would work in DAL.

I can provide logs on request (not sure to log right now).

Thanks!