No news I'm afraid.

(In reply to Carlo Caione from comment #17)
> In attachment what I get when using AMDGPU_GEM_DOMAIN_GTT.
[...]
> [drm:dm_plane_helper_prepare_fb [amdgpu]] *ERROR* Failed to pin framebuffer

Do you also get those errors with AMDGPU_GEM_DOMAIN_GTT? If so, it might be
interesting to track down the origin of the errors. Otherwise, it looks like
there's still something missing.