Comment 30 for bug 2039868

Created attachment 286575
kernel config 5.4.7 Fiji

Some additional info for my case:
- Running kernel 5.4.7 (vanilla), firmware 20191108 on gentoo
- Dmesg | grep -E "(drm)|(amdgpu)":
[ 3.930023] [drm] amdgpu kernel modesetting enabled.
[ 3.930217] amdgpu 0000:0a:00.0: remove_conflicting_pci_framebuffers: bar 0: 0xe0000000 -> 0xefffffff
[ 3.930219] amdgpu 0000:0a:00.0: remove_conflicting_pci_framebuffers: bar 2: 0xf0000000 -> 0xf01fffff
[ 3.930221] amdgpu 0000:0a:00.0: remove_conflicting_pci_framebuffers: bar 5: 0xfce00000 -> 0xfce3ffff
[ 3.930224] fb0: switching to amdgpudrmfb from EFI VGA
[ 3.930475] [drm] initializing kernel modesetting (FIJI 0x1002:0x7300 0x1002:0x0B36 0xCA).
[ 3.930486] [drm] register mmio base: 0xFCE00000
[ 3.930486] [drm] register mmio size: 262144
[ 3.930495] [drm] add ip block number 0 <vi_common>
[ 3.930495] [drm] add ip block number 1 <gmc_v8_0>
[ 3.930496] [drm] add ip block number 2 <tonga_ih>
[ 3.930497] [drm] add ip block number 3 <gfx_v8_0>
[ 3.930498] [drm] add ip block number 4 <sdma_v3_0>
[ 3.930498] [drm] add ip block number 5 <powerplay>
[ 3.930499] [drm] add ip block number 6 <dm>
[ 3.930500] [drm] add ip block number 7 <uvd_v6_0>
[ 3.930500] [drm] add ip block number 8 <vce_v3_0>
[ 3.930715] [drm] UVD is enabled in physical mode
[ 3.930715] [drm] VCE enabled in physical mode
[ 3.930743] [drm] vm size is 64 GB, 2 levels, block size is 10-bit, fragment size is 9-bit
[ 3.930751] amdgpu 0000:0a:00.0: VRAM: 4096M 0x000000F400000000 - 0x000000F4FFFFFFFF (4096M used)
[ 3.930753] amdgpu 0000:0a:00.0: GART: 1024M 0x000000FF00000000 - 0x000000FF3FFFFFFF
[ 3.930758] [drm] Detected VRAM RAM=4096M, BAR=256M
[ 3.930759] [drm] RAM width 512bits HBM
[ 3.930838] [drm] amdgpu: 4096M of VRAM memory ready
[ 3.930841] [drm] amdgpu: 4096M of GTT memory ready.
[ 3.930860] [drm] GART: num cpu pages 262144, num gpu pages 262144
[ 3.930928] [drm] PCIE GART of 1024M enabled (table at 0x000000F4001D5000).
[ 3.934174] [drm] Chained IB support enabled!
[ 3.940198] amdgpu: [powerplay] hwmgr_sw_init smu backed is fiji_smu
[ 3.941748] [drm] Found UVD firmware Version: 1.91 Family ID: 12
[ 3.941752] [drm] UVD ENC is disabled
[ 3.943542] [drm] Found VCE firmware Version: 55.2 Binary ID: 3
[ 4.009146] [drm] dce110_link_encoder_construct: Failed to get encoder_cap_info from VBIOS with error code 4!
[ 4.040084] [drm] Display Core initialized with v3.2.48!
[ 4.040542] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[ 4.040543] [drm] Driver supports precise vblank timestamp query.
[ 4.067774] [drm] UVD initialized successfully.
[ 4.168780] [drm] VCE initialized successfully.
[ 4.170163] [drm] Cannot find any crtc or sizes
[ 4.171948] [drm] Initialized amdgpu 3.35.0 20150101 for 0000:0a:00.0 on minor 0
[ 7.280062] amdgpu 0000:0a:00.0: [drm:amdgpu_ib_ring_tests [amdgpu]] *ERROR* IB test failed on uvd (-110).
[ 8.400365] amdgpu 0000:0a:00.0: [drm:amdgpu_ib_ring_tests [amdgpu]] *ERROR* IB test failed on vce0 (-110).
[ 8.400370] [drm:process_one_work] *ERROR* ib ring test failed (-110).