Up to date install of Debian (12.13) and Plasma (5.27.5), Radeon Video. When a user is logged in, the video for the Desktop display is distorted after:
--waking from sleep
--switching to a virtual terminal (example: Ctrl-alt-F2) and then switching back (Ctrl-alt-F1)
--Sometimes when switching to another user (i.e. more than one user logged on)
By “distorted” I mean the video is unreadable, as if the frame buffer is corrupted. The mouse cursor still works.
It only happens with a wayland session. It does not happen with a x11 session. I would say, I’d just use x11, but I’m afraid Plasma will drop support for x11 and then I’ll just have the problem again.
Note: I believe SDDM runs X11 on VT7. After logging in, a wayland session opens on VT1, where as a X11 session would open on VT7. I think that’s normal behavior. Curious if it could be a SDDM configuration problem.
The problem can usually be fixed with:
--Switching to VT7 (Ctrl-alt-F7) and switching back to the “distorted” VT (in most cases Ctrl-alt-F1). Note: when doing this, VT7 shows a “dead” login screen. I’m not sure that’s normal, my other working computer doesn't display this “dead” login screen.
--Opening a text terminal, logging in, and entering the command
$> kwin_wayland - -replace &
Any help is greatly appreciated!
system specifics:
$>uname -r
6.1.0-42-amd64
$>cat /etc/debian_version
12.13
$>plasmashell --version
plasmashell 5.27.5
$>lspci -k | grep -iEA3 '3d|vga'
01:05.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] RS780L [Radeon 3000]
Subsystem: Biostar Microtech Int'l Corp RS780L [Radeon 3000]
Kernel driver in use: radeon
Kernel modules: radeon, amdgpu
$>sudo dmidecode -t 2
# dmidecode 3.4
Getting SMBIOS data from sysfs.
SMBIOS 2.6 present.
Handle 0x0002, DMI type 2, 15 bytes
Base Board Information
Manufacturer: BIOSTAR Group
Product Name: A780L3C
Version:
Serial Number: None
Asset Tag: To Be Filled By O.E.M.
Features:
Board is a hosting board
Board is replaceable
Location In Chassis: To Be Filled By O.E.M.
Chassis Handle: 0x0003
Type: Motherboard
Contained Object Handles: 0
Statistics: Posted by kenking2 — 2026-02-04 15:47