https://bugs.freedesktop.org/show_bug.cgi?id=101499
--- Comment #15 from Carlo Caione carlo@caione.org --- Created attachment 132118 --> https://bugs.freedesktop.org/attachment.cgi?id=132118&action=edit journal_HDMI_detaching_corruption
Without seeing the corresponding Xorg log, I guess that's just a different symptom triggered by the same issue.
Attached the log. Yeah, not much different.
With an amd-staging-* kernel branch and DC enabled, you can try tweaking dce_v11_0_crtc_do_set_base to pass AMDGPU_GEM_DOMAIN_GTT instead of / in addition to AMDGPU_GEM_DOMAIN_VRAM to amdgpu_bo_pin. The DC code should already handle this correctly, but we're not sure whether or not there are additional constraints on system memory used for scanout. If there are, it probably won't work correctly yet.
I tried amd-staging-4.11 and interestingly dce_v11_0_crtc_do_set_base is called only when DC is disabled. When DRM_AMD_DC=y the function is never called.
I tried also to make the s/AMDGPU_GEM_DOMAIN_VRAM/AMDGPU_GEM_DOMAIN_GTT/ change with DC disabled. What I get is that I have some kind of intermittent display corruption when _connecting_ the HDMI cable on both the screens but on detaching at least everything is fine on the laptop panel.