Created attachment 142817 [details]
xubuntu 18.10 kernel with high loglevel

I see the number of problems reported on ASRock x470 + amd Ryzen 5 2400g during
boot:

$ grep  WARNING 4.18.0-13-generic.log 
[    3.938686] WARNING: CPU: 0 PID: 323 at
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link.c:1553
core_link_enable_stream+0x74c/0xc90 [amdgpu]
[    3.939285] WARNING: CPU: 0 PID: 323 at
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link.c:1582
core_link_enable_stream+0x78e/0xc90 [amdgpu]
[    3.939863] WARNING: CPU: 0 PID: 323 at
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link.c:1553
core_link_enable_stream+0x74c/0xc90 [amdgpu]
[    3.940450] WARNING: CPU: 0 PID: 323 at
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link.c:1572
core_link_enable_stream+0xacd/0xc90 [amdgpu]
[    3.941029] WARNING: CPU: 0 PID: 323 at
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link.c:1582
core_link_enable_stream+0x78e/0xc90 [amdgpu]
[    3.941610] WARNING: CPU: 0 PID: 323 at
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link.c:1553
core_link_enable_stream+0x74c/0xc90 [amdgpu]
[    3.942190] WARNING: CPU: 0 PID: 323 at
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link.c:1572
core_link_enable_stream+0xacd/0xc90 [amdgpu]
[    3.942766] WARNING: CPU: 0 PID: 323 at
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link.c:1582
core_link_enable_stream+0x78e/0xc90 [amdgpu]