Arch Linux

dllmr

Member

Registered: 2021-01-04

Posts: 7

[Solved] System unusable with mesa 1:25.3.1-2 (KDE Plasma, AMD)

After installing the latest round of mesa and vulkan updates yesterday, my system boots to an all white screen where SDDM is normally shown.

Downgrading mesa to 1:25.2.7-1 restores things. I couldn't see any obvious errors or warnings in the logs when it was failing.

My system is AMD Ryzen 5 5500U with AMD Lucienne [Integrated] and vulkan-radeon installed. The latter is still at 1:25.3.1-2 as dependency changes made a downgrade non-trivial.

Desktop is Plasma 6.5.3 with KWin (Wayland). Kernel version 6.17.9-arch1-1, but LTS had the same issue.

Any suggestions how to proceed please?

Mike

(edit) P.S. I also noticed some rendering issues immediately after the breaking upgrade, before the first reboot, so I don't think this is an SDDM issue per se.

Last edited by dllmr (2025-12-06 15:26:04)

seth

Member

From: Don't DM me only for attention

Registered: 2012-09-03

Posts: 71,526

Re: [Solved] System unusable with mesa 1:25.3.1-2 (KDE Plasma, AMD)

Test https://wiki.archlinux.org/title/SDDM#Wayland and if you've not been using the wayland backend, that please also post your Xorg log, https://wiki.archlinux.org/title/Xorg#General
Do you have xf86-video-amdgpu installed?

I couldn't see any obvious errors or warnings in the logs when it was failing.

What about the not-so-obvious errors?
"sudo journalctl -b" - anything amdgpu, sddm, Xorg, drm, fb, dri
Also, is this a hybrid graphics system?

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dllmr

Member

Registered: 2021-01-04

Posts: 7

Re: [Solved] System unusable with mesa 1:25.3.1-2 (KDE Plasma, AMD)

Thanks seth. The problem is not specific to SDDM. It still occurs after implementing the Wayland config change you suggested. I also tried switching to GDM and a similar problem occurs there - except the screen is black in the case of GDM, with only the mouse cursor visible (as it is with SDDM).

A closer analysis of journalctl output shows multiple errors loading shaders. The errors occur immediately after the SDDM greeter attempts to initialize displays:

Dec 06 14:18:54 puffin sddm-greeter-qt6[1153]: Adding view for "DP-1" QRect(0,0 1920x1080)
Dec 06 14:18:54 puffin sddm-greeter-qt6[1153]: Loading file:///usr/share/sddm/themes/breeze/Main.qml...
Dec 06 14:18:54 puffin sddm-greeter-qt6[1153]: Adding view for "HDMI-A-1" QRect(1920,0 1920x1080)
Dec 06 14:18:54 puffin sddm-helper-start-wayland[1112]: "ac_rtld error: !ehdr\n"
Dec 06 14:18:54 puffin sddm-helper-start-wayland[1112]: "ELF error: invalid `Elf' handle\nac_rtld error: !ehdr\nELF error: invalid `Elf' handle\nradeonsi: error: LLVM failed to upload shader\nradeonsi: error: ../mesa-25.3.1/src/gallium/drivers/radeonsi/si_state_shaders.cpp:2901 si_build_shader_variant - Failed to build shader variant (type=4)\n"
[... repeated 21 more times ...]

It's not a hybrid graphics system.

dllmr

Member

Registered: 2021-01-04

Posts: 7

Re: [Solved] System unusable with mesa 1:25.3.1-2 (KDE Plasma, AMD)

OK - I've resolved this. I had had to set a system-wide environment variable to work around an earlier Mesa bug, and it remained set:

AMD_DEBUG=notiling

Unsetting this fixes the shader issues and the system now runs normally.

seth

Member

From: Don't DM me only for attention

Registered: 2012-09-03

Posts: 71,526

Re: [Solved] System unusable with mesa 1:25.3.1-2 (KDE Plasma, AMD)

\o/
Please always remember to mark resolved threads by editing your initial posts subject - so others will know that there's no task left, but maybe a solution to find.
Thanks.

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