Hi folks,
A Fedora user, Mikhail (CCed), reported[0] a regression with their Vega 56 AMD GPU introduced by bfdec2340478 ("drm/amd/display: Implement dm_pp_get_clock_levels_by_type_with_latency"). The symptom is that nothing is displayed and looking at the logs (attached to the Bugzilla), I see gnome-shell is failing with "Failed to set CRTC mode 3840x2160: Invalid argument". The problem persists through 4.18 RC2 so it's not fixed by 10dd2b865393 ("drm/amd/display: Fix wrong latency assignment for VEGA clock levels").
I see a couple "if (!dm_pp_get_clock_levels_by_type_with_latency)" blocks which would no longer be unconditionally run, but I don't know enough to even guess at the problem.
[0] https://bugzilla.redhat.com/show_bug.cgi?id=1592110
Regards, Jeremy