Here are the kernel logs, foist for the failing boot, then a good boot. The failing 4.9 boot concludes with this:
[ 8.928400] amdgpu 0000:04:00.0: firmware: failed to load amdgpu/tonga_k_smc.bin (-2) [ 8.928982] amdgpu 0000:04:00.0: Direct firmware load for amdgpu/tonga_k_smc.bin failed with error -2 [ 8.929047] [drm:amdgpu_cgs_get_firmware_info [amdgpu]] *ERROR* Failed to request firmware [ 8.931250] [drm:amdgpu_device_init [amdgpu]] *ERROR* hw_init of IP block <amdgpu_powerplay> failed -22 [ 8.931924] amdgpu 0000:04:00.0: amdgpu_init failed [ 9.070724] [drm] amdgpu: ttm finalized [ 9.070729] amdgpu 0000:04:00.0: Fatal error during GPU init [ 9.071176] [drm] amdgpu: finishing device. [ 9.072293] amdgpu: probe of 0000:04:00.0 failed with error -22 The full failing log (cat /var/log/kern.log |grep amdgpu) [ 7.796676] [drm] amdgpu kernel modesetting enabled. [ 7.796676] [drm] amdgpu kernel modesetting enabled. [ 8.088460] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_mc.bin [ 8.088479] amdgpu 0000:04:00.0: VRAM: 4096M 0x0000000000000000 - 0x00000000FFFFFFFF (4096M used) [ 8.088482] amdgpu 0000:04:00.0: GTT: 64455M 0x0000000100000000 - 0x00000010BC7BFFFF [ 8.088514] [drm] amdgpu: 4096M of VRAM memory ready [ 8.088515] [drm] amdgpu: 64455M of GTT memory ready. [ 8.090690] amdgpu 0000:04:00.0: amdgpu: using MSI. [ 8.090733] [drm] amdgpu: irq initialized. [ 8.103523] amdgpu: powerplay initialized [ 8.088460] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_mc.bin [ 8.088479] amdgpu 0000:04:00.0: VRAM: 4096M 0x0000000000000000 - 0x00000000FFFFFFFF (4096M used) [ 8.088482] amdgpu 0000:04:00.0: GTT: 64455M 0x0000000100000000 - 0x00000010BC7BFFFF [ 8.088514] [drm] amdgpu: 4096M of VRAM memory ready [ 8.088515] [drm] amdgpu: 64455M of GTT memory ready. [ 8.090690] amdgpu 0000:04:00.0: amdgpu: using MSI. [ 8.090733] [drm] amdgpu: irq initialized. [ 8.103523] amdgpu: powerplay initialized [ 8.227899] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_pfp.bin [ 8.232122] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_me.bin [ 8.233481] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_ce.bin [ 8.236718] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_rlc.bin [ 8.243021] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_mec.bin [ 8.253097] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_mec2.bin [ 8.255167] amdgpu 0000:04:00.0: fence driver on ring 0 use gpu addr 0x0000000100000008, cpu addr 0xffff9996e2693008 [ 8.255733] amdgpu 0000:04:00.0: fence driver on ring 1 use gpu addr 0x0000000100000018, cpu addr 0xffff9996e2693018 [ 8.256248] amdgpu 0000:04:00.0: fence driver on ring 2 use gpu addr 0x0000000100000028, cpu addr 0xffff9996e2693028 [ 8.256511] amdgpu 0000:04:00.0: fence driver on ring 3 use gpu addr 0x0000000100000038, cpu addr 0xffff9996e2693038 [ 8.256772] amdgpu 0000:04:00.0: fence driver on ring 4 use gpu addr 0x0000000100000048, cpu addr 0xffff9996e2693048 [ 8.257009] amdgpu 0000:04:00.0: fence driver on ring 5 use gpu addr 0x0000000100000058, cpu addr 0xffff9996e2693058 [ 8.257272] amdgpu 0000:04:00.0: fence driver on ring 6 use gpu addr 0x0000000100000068, cpu addr 0xffff9996e2693068 [ 8.257537] amdgpu 0000:04:00.0: fence driver on ring 7 use gpu addr 0x0000000100000078, cpu addr 0xffff9996e2693078 [ 8.258034] amdgpu 0000:04:00.0: fence driver on ring 8 use gpu addr 0x0000000100000088, cpu addr 0xffff9996e2693088 [ 8.261506] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_sdma.bin [ 8.282969] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_sdma1.bin [ 8.283235] amdgpu 0000:04:00.0: fence driver on ring 9 use gpu addr 0x0000000100000098, cpu addr 0xffff9996e2693098 [ 8.283884] amdgpu 0000:04:00.0: fence driver on ring 10 use gpu addr 0x00000001000000a8, cpu addr 0xffff9996e26930a8 [ 8.294951] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_uvd.bin [ 8.297786] amdgpu 0000:04:00.0: fence driver on ring 11 use gpu addr 0x0000000007e747b0, cpu addr 0xffffb6c4ce24e7b0 [ 8.298894] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_vce.bin [ 8.299152] amdgpu 0000:04:00.0: fence driver on ring 12 use gpu addr 0x00000001000000c8, cpu addr 0xffff9996e26930c8 [ 8.299287] amdgpu 0000:04:00.0: fence driver on ring 13 use gpu addr 0x00000001000000d8, cpu addr 0xffff9996e26930d8 [ 8.928400] amdgpu 0000:04:00.0: firmware: failed to load amdgpu/tonga_k_smc.bin (-2) [ 8.928982] amdgpu 0000:04:00.0: Direct firmware load for amdgpu/tonga_k_smc.bin failed with error -2 [ 8.929047] [drm:amdgpu_cgs_get_firmware_info [amdgpu]] *ERROR* Failed to request firmware [ 8.931250] [drm:amdgpu_device_init [amdgpu]] *ERROR* hw_init of IP block <amdgpu_powerplay> failed -22 [ 8.931924] amdgpu 0000:04:00.0: amdgpu_init failed [ 9.070724] [drm] amdgpu: ttm finalized [ 9.070729] amdgpu 0000:04:00.0: Fatal error during GPU init [ 9.071176] [drm] amdgpu: finishing device. [ 9.072293] amdgpu: probe of 0000:04:00.0 failed with error -22 working boot of kernel 4.8: [ 7.164859] [drm] amdgpu kernel modesetting enabled. [ 7.306409] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_mc.bin [ 7.306423] amdgpu 0000:04:00.0: VRAM: 4096M 0x0000000000000000 - 0x00000000FFFFFFFF (4096M used) [ 7.306425] amdgpu 0000:04:00.0: GTT: 4096M 0x0000000100000000 - 0x00000001FFFFFFFF [ 7.306578] [drm] amdgpu: 4096M of VRAM memory ready [ 7.306579] [drm] amdgpu: 4096M of GTT memory ready. [ 7.308574] amdgpu 0000:04:00.0: amdgpu: using MSI. [ 7.308721] [drm] amdgpu: irq initialized. [ 7.164859] [drm] amdgpu kernel modesetting enabled. [ 7.306409] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_mc.bin [ 7.306423] amdgpu 0000:04:00.0: VRAM: 4096M 0x0000000000000000 - 0x00000000FFFFFFFF (4096M used) [ 7.306425] amdgpu 0000:04:00.0: GTT: 4096M 0x0000000100000000 - 0x00000001FFFFFFFF [ 7.306578] [drm] amdgpu: 4096M of VRAM memory ready [ 7.306579] [drm] amdgpu: 4096M of GTT memory ready. [ 7.308574] amdgpu 0000:04:00.0: amdgpu: using MSI. [ 7.308721] [drm] amdgpu: irq initialized. [ 7.335394] amdgpu: powerplay initialized [ 7.336488] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_pfp.bin [ 7.337102] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_me.bin [ 7.337749] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_ce.bin [ 7.338018] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_rlc.bin [ 7.340219] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_mec.bin [ 7.341951] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_mec2.bin [ 7.342113] amdgpu 0000:04:00.0: fence driver on ring 0 use gpu addr 0x0000000100000008, cpu addr 0xffff8f086571e008 [ 7.342225] amdgpu 0000:04:00.0: fence driver on ring 1 use gpu addr 0x0000000100000018, cpu addr 0xffff8f086571e018 [ 7.342285] amdgpu 0000:04:00.0: fence driver on ring 2 use gpu addr 0x0000000100000028, cpu addr 0xffff8f086571e028 [ 7.342343] amdgpu 0000:04:00.0: fence driver on ring 3 use gpu addr 0x0000000100000038, cpu addr 0xffff8f086571e038 [ 7.342418] amdgpu 0000:04:00.0: fence driver on ring 4 use gpu addr 0x0000000100000048, cpu addr 0xffff8f086571e048 [ 7.342474] amdgpu 0000:04:00.0: fence driver on ring 5 use gpu addr 0x0000000100000058, cpu addr 0xffff8f086571e058 [ 7.342548] amdgpu 0000:04:00.0: fence driver on ring 6 use gpu addr 0x0000000100000068, cpu addr 0xffff8f086571e068 [ 7.342663] amdgpu 0000:04:00.0: fence driver on ring 7 use gpu addr 0x0000000100000078, cpu addr 0xffff8f086571e078 [ 7.342729] amdgpu 0000:04:00.0: fence driver on ring 8 use gpu addr 0x0000000100000088, cpu addr 0xffff8f086571e088 [ 7.343089] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_sdma.bin [ 7.343371] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_sdma1.bin [ 7.343439] amdgpu 0000:04:00.0: fence driver on ring 9 use gpu addr 0x0000000100000098, cpu addr 0xffff8f086571e098 [ 7.343514] amdgpu 0000:04:00.0: fence driver on ring 10 use gpu addr 0x00000001000000a8, cpu addr 0xffff8f086571e0a8 [ 7.335394] amdgpu: powerplay initialized [ 7.336488] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_pfp.bin [ 7.337102] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_me.bin [ 7.337749] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_ce.bin [ 7.338018] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_rlc.bin [ 7.340219] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_mec.bin [ 7.341951] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_mec2.bin [ 7.342113] amdgpu 0000:04:00.0: fence driver on ring 0 use gpu addr 0x0000000100000008, cpu addr 0xffff8f086571e008 [ 7.342225] amdgpu 0000:04:00.0: fence driver on ring 1 use gpu addr 0x0000000100000018, cpu addr 0xffff8f086571e018 [ 7.342285] amdgpu 0000:04:00.0: fence driver on ring 2 use gpu addr 0x0000000100000028, cpu addr 0xffff8f086571e028 [ 7.342343] amdgpu 0000:04:00.0: fence driver on ring 3 use gpu addr 0x0000000100000038, cpu addr 0xffff8f086571e038 [ 7.342418] amdgpu 0000:04:00.0: fence driver on ring 4 use gpu addr 0x0000000100000048, cpu addr 0xffff8f086571e048 [ 7.342474] amdgpu 0000:04:00.0: fence driver on ring 5 use gpu addr 0x0000000100000058, cpu addr 0xffff8f086571e058 [ 7.342548] amdgpu 0000:04:00.0: fence driver on ring 6 use gpu addr 0x0000000100000068, cpu addr 0xffff8f086571e068 [ 7.342663] amdgpu 0000:04:00.0: fence driver on ring 7 use gpu addr 0x0000000100000078, cpu addr 0xffff8f086571e078 [ 7.342729] amdgpu 0000:04:00.0: fence driver on ring 8 use gpu addr 0x0000000100000088, cpu addr 0xffff8f086571e088 [ 7.343089] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_sdma.bin [ 7.343371] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_sdma1.bin [ 7.343439] amdgpu 0000:04:00.0: fence driver on ring 9 use gpu addr 0x0000000100000098, cpu addr 0xffff8f086571e098 [ 7.343514] amdgpu 0000:04:00.0: fence driver on ring 10 use gpu addr 0x00000001000000a8, cpu addr 0xffff8f086571e0a8 [ 7.345250] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_uvd.bin [ 7.345756] amdgpu 0000:04:00.0: fence driver on ring 11 use gpu addr 0x00000000008907b0, cpu addr 0xffffc85b8dc4e7b0 [ 7.346810] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_vce.bin [ 7.346971] amdgpu 0000:04:00.0: fence driver on ring 12 use gpu addr 0x00000001000000c8, cpu addr 0xffff8f086571e0c8 [ 7.347035] amdgpu 0000:04:00.0: fence driver on ring 13 use gpu addr 0x00000001000000d8, cpu addr 0xffff8f086571e0d8 [ 7.437084] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_smc.bin [ 8.030673] fbcon: amdgpudrmfb (fb0) is primary device [ 8.463697] amdgpu 0000:04:00.0: fb0: amdgpudrmfb frame buffer device [ 8.485124] [drm] Initialized amdgpu 3.3.0 20150101 for 0000:04:00.0 on minor 0 [ 7.345250] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_uvd.bin [ 7.345756] amdgpu 0000:04:00.0: fence driver on ring 11 use gpu addr 0x00000000008907b0, cpu addr 0xffffc85b8dc4e7b0 [ 7.346810] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_vce.bin [ 7.346971] amdgpu 0000:04:00.0: fence driver on ring 12 use gpu addr 0x00000001000000c8, cpu addr 0xffff8f086571e0c8 [ 7.347035] amdgpu 0000:04:00.0: fence driver on ring 13 use gpu addr 0x00000001000000d8, cpu addr 0xffff8f086571e0d8 [ 7.437084] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_smc.bin [ 8.030673] fbcon: amdgpudrmfb (fb0) is primary device [ 8.463697] amdgpu 0000:04:00.0: fb0: amdgpudrmfb frame buffer device [ 8.485124] [drm] Initialized amdgpu 3.3.0 20150101 for 0000:04:00.0 on minor 0 [ 19.093400] [drm:dce_v10_0_afmt_setmode [amdgpu]] *ERROR* Couldn't read SADs: 0 [ 19.093400] [drm:dce_v10_0_afmt_setmode [amdgpu]] *ERROR* Couldn't read SADs: 0 [ 5579.826039] [drm:dce_v10_0_afmt_setmode [amdgpu]] *ERROR* Couldn't read SADs: 0 [ 5579.826039] [drm:dce_v10_0_afmt_setmode [amdgpu]] *ERROR* Couldn't read SADs: 0 [ 5599.777133] [drm:dce_v10_0_afmt_setmode [amdgpu]] *ERROR* Couldn't read SADs: 0 [ 5599.777133] [drm:dce_v10_0_afmt_setmode [amdgpu]] *ERROR* Couldn't read SADs: 0 [ 5735.150462] [drm:dce_v10_0_afmt_setmode [amdgpu]] *ERROR* Couldn't read SADs: 0 [ 5735.150462] [drm:dce_v10_0_afmt_setmode [amdgpu]] *ERROR* Couldn't read SADs: 0 [ 6019.093174] [drm:dce_v10_0_afmt_setmode [amdgpu]] *ERROR* Couldn't read SADs: 0 [ 6019.093174] [drm:dce_v10_0_afmt_setmode [amdgpu]] *ERROR* Couldn't read SADs: 0 [ 6040.356159] [drm:dce_v10_0_afmt_setmode [amdgpu]] *ERROR* Couldn't read SADs: 0 [ 6040.356159] [drm:dce_v10_0_afmt_setmode [amdgpu]] *ERROR* Couldn't read SADs: 0 [ 6168.342155] [drm:dce_v10_0_afmt_setmode [amdgpu]] *ERROR* Couldn't read SADs: 0 [ 6168.342155] [drm:dce_v10_0_afmt_setmode [amdgpu]] *ERROR* Co