Package: linux-image-4.9.0-1-amd64 Version: 4.9.6-3 Everything works under kernel 4.8, but have display problems with x-server, virtual terminals when booting 4.9. Diffs reveal that the two kernels load different firmware for the graphics card.
Symptoms: graphics card is wired up to drive three displays. When xserver/gdm greater starts, third screen never lights up; monitor states "no input signal". virtual terminal switching (alt-pf1 through alt-pf6) fails to change the display. The vt switch did occur: I can blindly login to a virtual terminal, and run commands in it; display stays frozen. Killing/starting X11 fails to do anything at all to display: no blinking, no refresh; display is frozen. Graphics hardware: 04:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Tonga PRO [Radeon R9 285/380] (rev f1) Diffing the failed and the good boots, I see different firmware being loaded for these two kernels. Failing boot loads amdgpu/tonga_k_smc.bin while the working boot loads amdgpu/tonga_smc.bin Failing boot looks like this: cat /var/log/kern.log |grep firmware Feb 9 21:52:37 fanny kernel: [ 4.240162] GHES: APEI firmware first mode is enabled by WHEA _OSC. Feb 9 21:52:37 fanny kernel: [ 10.419654] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_mc.bin Feb 9 21:52:37 fanny kernel: [ 10.448529] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_pfp.bin Feb 9 21:52:37 fanny kernel: [ 10.462440] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_me.bin Feb 9 21:52:37 fanny kernel: [ 10.468253] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_ce.bin Feb 9 21:52:37 fanny kernel: [ 10.475209] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_rlc.bin Feb 9 21:52:37 fanny kernel: [ 10.477127] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_mec.bin Feb 9 21:52:37 fanny kernel: [ 10.478621] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_mec2.bin Feb 9 21:52:37 fanny kernel: [ 10.480364] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_sdma.bin Feb 9 21:52:37 fanny kernel: [ 10.480600] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_sdma1.bin Feb 9 21:52:37 fanny kernel: [ 10.482542] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_uvd.bin Feb 9 21:52:37 fanny kernel: [ 10.482548] [drm] Found UVD firmware Version: 1.65 Family ID: 10 Feb 9 21:52:37 fanny kernel: [ 10.483839] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_vce.bin Feb 9 21:52:37 fanny kernel: [ 10.483844] [drm] Found VCE firmware Version: 52.8 Binary ID: 3 Feb 9 21:52:37 fanny kernel: [ 10.681430] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_k_smc.bin Working boot looks like this: cat /var/log/kern.log |grep firmware Feb 9 21:56:39 fanny kernel: [ 4.123908] GHES: APEI firmware first mode is enabled by WHEA _OSC. Feb 9 21:56:39 fanny kernel: [ 9.326443] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_mc.bin Feb 9 21:56:39 fanny kernel: [ 9.738087] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_pfp.bin Feb 9 21:56:39 fanny kernel: [ 9.738518] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_me.bin Feb 9 21:56:39 fanny kernel: [ 9.738820] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_ce.bin Feb 9 21:56:39 fanny kernel: [ 9.739161] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_rlc.bin Feb 9 21:56:39 fanny kernel: [ 9.745141] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_mec.bin Feb 9 21:56:39 fanny kernel: [ 9.746675] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_mec2.bin Feb 9 21:56:39 fanny kernel: [ 9.747554] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_sdma.bin Feb 9 21:56:39 fanny kernel: [ 9.747784] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_sdma1.bin Feb 9 21:56:39 fanny kernel: [ 9.749821] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_uvd.bin Feb 9 21:56:39 fanny kernel: [ 9.749828] [drm] Found UVD firmware Version: 1.65 Family ID: 10 Feb 9 21:56:39 fanny kernel: [ 9.751288] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_vce.bin Feb 9 21:56:39 fanny kernel: [ 9.751293] [drm] Found VCE firmware Version: 52.8 Binary ID: 3 Feb 9 21:56:39 fanny kernel: [ 9.854098] amdgpu 0000:04:00.0: firmware: direct-loading firmware amdgpu/tonga_smc.bin
