SDDM crashes resuming from Sleep?

[Snowhog]

I assume that is what's happening. I put the PC to Sleep, sometimes with Firefox open; most of the time with any running application closed. When I have the PC resume from Sleep; pressing any key; sometimes all I get is a black screen with a functioning mouse; the cursor moves. This happens several times a month.

I reboot using the Magic Key Sequence: Alt+Prnt+REISUB; and I am able to log in just fine. How can I diagnose this? Is SDDM actually crashing? Can I do something to restart it without having to do the clean process shutdown and reboot?

[die.boer]

when it happens again ,after reboot check logs

journalctl -b -1 -p 3

Look for:GPU errors , kwin crashes , segfaults

also , to see if it is actually SDDM...when it happens again,switch to TTY
If you get a login prompt,your system is alive...not SDDM
If TTY is also dead...deeper kernel/GPU issue

[die.boer]

Try recovering without reboot
When it happens: Restart your graphical session (not full reboot)
From TTY:

systemctl restart display-manager

This restarts SDDM, logging you out but avoiding a full reboot.

[wonder]

I assume that is what's happening. I put the PC to Sleep, sometimes with Firefox open; most of the time with any running application closed. When I have the PC resume from Sleep; pressing any key; sometimes all I get is a black screen with a functioning mouse; the cursor moves. This happens several times a month.

I reboot using the Magic Key Sequence: Alt+Prnt+REISUB; and I am able to log in just fine. How can I diagnose this? Is SDDM actually crashing? Can I do something to restart it without having to do the clean process shutdown and reboot?

What GPU do you have and what kernel version?
I had a similar problem, and it was the combination of GPU and that kernel...

[srllucas]

I have an issue with KDE + Wayland (X11 works normally), and I don’t know if it’s related to this topic. I can’t run any recent KDE + Wayland distribution. After the splash screen, the monitor goes to sleep. The system itself is still running — for example, I can access it through TTY (and the monitor wakes up again after switching to a TTY). In KDE, there is no active display in $DISPLAY. GNOME works normally, and I’m currently using Ubuntu for the reason I explained here (even though I love Kubuntu!).

System:
Host: luciano-X99-B9 Kernel: 7.0.0-15-generic arch: x86_64 bits: 64
Desktop: GNOME v: 50.1 Distro: Ubuntu 26.04 (Resolute Raccoon)
Machine:
Type: Desktop Mobo: MACHINIST model: X99 B9 serial: <superuser required>
Firmware: UEFI vendor: American Megatrends v: 5.11 date: 06/07/2024
CPU:
Info: 14-core Intel Xeon E5-2680 v4 [MT MCP] speed (MHz): avg: 1200
min/max: 1200/3300
Graphics:
Device-1: Advanced Micro Devices [AMD/ATI] Ellesmere [Radeon RX
470/480/570/570X/580/580X/590] driver: amdgpu v: kernel
Display: wayland server: X.Org v: 24.1.10 with: Xwayland v: 24.1.10
compositor: gnome-shell driver: dri: radeonsi gpu: amdgpu
resolution: 1920x1080~60Hz
API: OpenGL v: 4.6 compat-v: 4.5 vendor: amd mesa v: 26.0.3-1ubuntu1
renderer: AMD Radeon RX 570 Series (radeonsi polaris10 ACO DRM 3.64
7.0.0-15-generic)
Info: Tools: api: eglinfo, glxinfo, vulkaninfo gpu: corectrl x11: xdriinfo,
xdpyinfo, xprop, xrandr
Network:
Device-1: Realtek RTL8111/8168/8211/8411 PCI Express Gigabit Ethernet
driver: r8169
Drives:
Local Storage: total: 1.35 TiB used: 63.36 GiB (4.6%)
Info:
Memory: total: 64 GiB available: 61.63 GiB used: 3.44 GiB (5.6%)
Processes: 497 Uptime: 25m Shell: Bash inxi: 3.3.40

[die.boer]

and I don’t know if it’s related to this topic.

prolly better to start a new topic

[wonder]

I have an issue with KDE + Wayland (X11 works normally), and I don’t know if it’s related to this topic. I can’t run any recent KDE + Wayland distribution. After the splash screen, the monitor goes to sleep. The system itself is still running — for example, I can access it through TTY (and the monitor wakes up again after switching to a TTY). In KDE, there is no active display in $DISPLAY. GNOME works normally, and I’m currently using Ubuntu for the reason I explained here (even though I love Kubuntu!).

System:
Host: luciano-X99-B9 Kernel: 7.0.0-15-generic arch: x86_64 bits: 64
Desktop: GNOME v: 50.1 Distro: Ubuntu 26.04 (Resolute Raccoon)
Machine:
Type: Desktop Mobo: MACHINIST model: X99 B9 serial: <superuser required>
Firmware: UEFI vendor: American Megatrends v: 5.11 date: 06/07/2024
CPU:
Info: 14-core Intel Xeon E5-2680 v4 [MT MCP] speed (MHz): avg: 1200
min/max: 1200/3300
Graphics:
Device-1: Advanced Micro Devices [AMD/ATI] Ellesmere [Radeon RX
470/480/570/570X/580/580X/590] driver: amdgpu v: kernel
Display: wayland server: X.Org v: 24.1.10 with: Xwayland v: 24.1.10
compositor: gnome-shell driver: dri: radeonsi gpu: amdgpu
resolution: 1920x1080~60Hz
API: OpenGL v: 4.6 compat-v: 4.5 vendor: amd mesa v: 26.0.3-1ubuntu1
renderer: AMD Radeon RX 570 Series (radeonsi polaris10 ACO DRM 3.64
7.0.0-15-generic)
Info: Tools: api: eglinfo, glxinfo, vulkaninfo gpu: corectrl x11: xdriinfo,
xdpyinfo, xprop, xrandr
Network:
Device-1: Realtek RTL8111/8168/8211/8411 PCI Express Gigabit Ethernet
driver: r8169
Drives:
Local Storage: total: 1.35 TiB used: 63.36 GiB (4.6%)
Info:
Memory: total: 64 GiB available: 61.63 GiB used: 3.44 GiB (5.6%)
Processes: 497 Uptime: 25m Shell: Bash inxi: 3.3.40

As others have mentioned, it's best to start a new thread. In any case, you should specify the kernel version and driver.
What happened to me was specifically a kernel issue with Polaris; changing the kernel version fixed it. I wasn't using Wayland (I just tried it on a Kubuntu 26.04 installation, but I had to revert to X11).

[skyfishgoo]

expecting wayland to work on 24.04 is a fools errand... just use X11 until you upgrade to 26.06 where most of these issues have been ironed out.