Distribution
Linux Mint 22.3 Zena, Cinnamon edition
Cinnamon version
Cinnamon 6.6.7
Muffin 6.6.3
LightDM 1.30.0
Kernel and graphics stack
Kernel: 6.17.0-35-generic
Base: Ubuntu 24.04 noble
Session: X11 / X.Org 21.1.11
GPU: AMD Picasso/Raven 2 / Radeon Vega 8 Graphics
Driver: amdgpu kernel driver
Mesa: 25.2.8-0ubuntu0.24.04.1
Display: HDMI-A-1, 1366x768 @ 60 Hz
Issue
The actual failure was a black screen / graphical output failure while the machine was still running.
After the screen went black I tried several keyboard shortcuts to recover or switch consoles, including combinations such as Ctrl+Alt+F2/F4/F5/F7, Ctrl+Alt+R, and Ctrl+Alt+Backspace. Because of that, the later LightDM login/session-close events may have been caused by my recovery attempts and should not be treated as the primary bug.
This did not look like a full system reboot: uptime and wtmp showed the machine had been running since the previous day. The evidence points to a graphics/display stack failure, with later session changes possibly triggered by my key combinations while trying to recover from the black screen.
This may ultimately be a kernel/amdgpu issue, but I am reporting it here because the visible failure happened in a Linux Mint Cinnamon graphical session.
Timeline from journal
Important: entries after the black screen may reflect my recovery attempts with keyboard shortcuts, not necessarily the original trigger.
Jun 04 11:00:41 linuxmint systemd[1351]: gnome-terminal-server.service: Main process exited, code=exited, status=1/FAILURE
Jun 04 11:00:41 linuxmint systemd[1351]: gnome-terminal-server.service: Failed with result 'exit-code'.
Jun 04 11:00:42 linuxmint cinnamon-screen[1766817]: cannot open display: :0
Jun 04 11:00:43 linuxmint cinnamon-session-binary[1392]: WARNING: t+55402.01331s: Application 'cinnamon.desktop' killed by signal 15
Jun 04 11:00:43 linuxmint cinnamon-session-binary[1392]: WARNING: t+55402.01335s: App 'cinnamon.desktop' respawning too quickly
Jun 04 11:00:43 linuxmint cinnamon-session-binary[1392]: CRITICAL: t+55402.01336s: Unable to start session: A program required by the session failed to start. App ID: 'cinnamon.desktop'. Startup ID: '1048204353e53d03c3178052624940397500000013920000'.
Jun 04 11:00:44 linuxmint lightdm[1766870]: pam_unix(lightdm-greeter:session): session opened for user lightdm(uid=113) by (uid=0)
Jun 04 11:00:44 linuxmint systemd-logind[896]: New session c3 of user lightdm.
Jun 04 11:00:45 linuxmint lightdm[1297]: pam_unix(lightdm:session): session closed for user pablo
Jun 04 11:00:45 linuxmint systemd-logind[896]: Removed session c2.
Jun 04 11:00:56 linuxmint (sd-pam)[1352]: pam_unix(systemd-user:session): session closed for user pablo
Jun 04 11:01:12 linuxmint kernel: amdgpu 0000:06:00.0: [drm] REG_WAIT timeout 1us * 200 tries - hubp1_set_blank line:60
Jun 04 11:02:08 linuxmint lightdm[1766980]: pam_unix(lightdm:session): session opened for user pablo(uid=1000) by (uid=0)
Jun 04 11:02:08 linuxmint systemd-logind[896]: Removed session c3.
Jun 04 11:02:08 linuxmint systemd-logind[896]: New session c4 of user pablo.
There was also a very large amount of repeated kernel log spam around the same time:
amdgpu 0000:06:00.0: [drm] pstate TEST_DEBUG_DATA: 0x3FF60000
amdgpu 0000:06:00.0: [drm] pstate TEST_DEBUG_DATA: 0x37F60000
Expected behavior
The display should not go black while the system is still running. If the display/GPU stack has a transient failure, the session should recover when possible or leave clearer crash information.
Actual behavior
The screen went black. While trying to recover, I used several keyboard shortcuts. After that, LightDM was shown and logging in again started a new session.
Notes
This was observed once so far. I can provide more complete journal excerpts if needed, but the raw log around the event is extremely noisy because of the repeated amdgpu pstate TEST_DEBUG_DATA messages.
Distribution
Linux Mint 22.3 Zena, Cinnamon edition
Cinnamon version
Cinnamon 6.6.7
Muffin 6.6.3
LightDM 1.30.0
Kernel and graphics stack
Kernel: 6.17.0-35-generic
Base: Ubuntu 24.04 noble
Session: X11 / X.Org 21.1.11
GPU: AMD Picasso/Raven 2 / Radeon Vega 8 Graphics
Driver: amdgpu kernel driver
Mesa: 25.2.8-0ubuntu0.24.04.1
Display: HDMI-A-1, 1366x768 @ 60 Hz
Issue
The actual failure was a black screen / graphical output failure while the machine was still running.
After the screen went black I tried several keyboard shortcuts to recover or switch consoles, including combinations such as Ctrl+Alt+F2/F4/F5/F7, Ctrl+Alt+R, and Ctrl+Alt+Backspace. Because of that, the later LightDM login/session-close events may have been caused by my recovery attempts and should not be treated as the primary bug.
This did not look like a full system reboot: uptime and wtmp showed the machine had been running since the previous day. The evidence points to a graphics/display stack failure, with later session changes possibly triggered by my key combinations while trying to recover from the black screen.
This may ultimately be a kernel/amdgpu issue, but I am reporting it here because the visible failure happened in a Linux Mint Cinnamon graphical session.
Timeline from journal
Important: entries after the black screen may reflect my recovery attempts with keyboard shortcuts, not necessarily the original trigger.
There was also a very large amount of repeated kernel log spam around the same time:
Expected behavior
The display should not go black while the system is still running. If the display/GPU stack has a transient failure, the session should recover when possible or leave clearer crash information.
Actual behavior
The screen went black. While trying to recover, I used several keyboard shortcuts. After that, LightDM was shown and logging in again started a new session.
Notes
This was observed once so far. I can provide more complete journal excerpts if needed, but the raw log around the event is extremely noisy because of the repeated amdgpu
pstate TEST_DEBUG_DATAmessages.