SDDM freezes sometimes on cold boot


I am having this weird problem, sometimes when I boot my system SDDM takes no input.
When it happens I can’t input anything using the keyboard or the mouse. At the same time can move the mouse cursor around and also I can switch to another tty, it feels like SDDM is unresponsive.

I also compared the logs of SDDM when it hangs vs a normal boot. I couldn’t find any difference.

I already deleted ~/.Xauthority, like some threads suggested, unfortunately without success.

My system information:

  Host: kai-desktop Kernel: 6.4.16-5-MANJARO arch: x86_64 bits: 64
    Desktop: KDE Plasma v: 5.27.8 Distro: Manjaro Linux
  Type: Desktop System: ASUS product: N/A v: N/A serial: <superuser required>
  Mobo: ASUSTeK model: PRIME X670E-PRO WIFI v: Rev 1.xx
    serial: <superuser required> UEFI: American Megatrends v: 1654
    date: 08/25/2023
  Info: 8-core model: AMD Ryzen 7 7800X3D bits: 64 type: MT MCP cache:
    L2: 8 MiB
  Speed (MHz): avg: 3181 min/max: 3000/5049 cores: 1: 3000 2: 3000 3: 3000
    4: 3000 5: 3000 6: 3000 7: 3000 8: 3790 9: 3000 10: 2771 11: 3000 12: 3000
    13: 2950 14: 4200 15: 3000 16: 4200
  Device-1: AMD Navi 31 [Radeon RX 7900 XT/7900 XTX] driver: amdgpu v: kernel
  Display: wayland server: v: with: Xwayland v: 23.2.1
    compositor: kwin_wayland driver: X: loaded: amdgpu
    unloaded: modesetting,radeon dri: radeonsi gpu: amdgpu resolution:
    1: 2560x1440 2: 1920x1080
  API: EGL v: 1.5 drivers: kms_swrast,radeonsi,swrast
    platforms: gbm,wayland,x11,surfaceless,device
  API: OpenGL v: 4.6 compat-v: 4.5 vendor: amd mesa v: 23.2.1-arch1.1
    renderer: AMD Radeon RX 7900 XT (gfx1100 LLVM 16.0.6 DRM 3.52
  API: Vulkan v: 1.3.264 drivers: radv surfaces: xcb,xlib,wayland

I have the same issue with my main computer at home: When I boot the machine from a cold state (complete power down: unplugged, or power failure, or rear power switch was turned “Off”), if i attempt to boot normally, then immediately after logging in, I get one of these:

  1. Display alternates between all-white and all black screens, 5sec each, forever; mouse and keyboard do nothing

  2. Display looks normal, but mouse and keyboard do nothing.

It’s been doing that for months. Maybe SDDM, or maybe something else. I never found a solution from within Manjaro, but I did find a work-around that works every time: When the BIOS password screen comes up (I have that enabled) I push the front panel “Reset” button. Then the second time the BIOS password screen pops up, I log-in to BIOS, then hit “Enter” on the Grub screen, then log-in normally on the GUI Manjaro Linux log-in screen, and everything works. Something not getting fully reset on power-up? Try pressing your front panel “Reset” button (if you have one) a few seconds after every power-up, and see if your problem goes away. (If no “Reset” button, long-press the front-panel “On/Off” button until the system shuts down, wait 10 sec, then short-press “On/Off”.) May not work (if your symptoms are from a different cause), but can’t hurt, so worth trying.

No quick fix here; but, for what it’s worth, I have also experienced what you describe:

Usually, after waiting 30 seconds, or similar, I was able to again enter text in the login screen inputs. What caused it, I don’t know; it was on an older machine with less resources; however, I suspect it was simply that background processes and/or support for applications starting at login had not yet finished loading. Using a keyboard and mouse (Logitech) with a wireless USB receiver probably added to the delay.

I still can switch to another TTY session, then I usually type reboot or start another X session. It seems to be a problem with SDDM since my keyboard works well…

I also noticed that I can also restart sddm with “systemctl restart sddm”. Still it’s annoying. I also found an open issue here which sounds similar: Issue with starting sessions on first launch · Issue #1800 · sddm/sddm · GitHub

Do you have an AMD System and maybe with X670 chipset?

Intel, Z490 here.

Thet kernel is EOL, switch to a supported one:

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Did that a week ago. Switching kernels around didn’t change the behavior.