Dear Maintainer,

This is a report of a system-wide failure of core KDE Plasma services on a fresh installation of Debian 13 "Trixie". The primary symptom is that screen brightness cannot be controlled via the DE, but it affects other services as well.

NOTE: This issue is specific to this Debian 13 installation. Brightness controls work correctly on another KDE installation, which suggests the problem is with the packaging or integration within Debian.

HARDWARE:
- Laptop with an AMD Radeon 780M iGPU and an NVIDIA RTX 4050 dGPU.
- The laptop display is connected to the AMD iGPU.

SYMPTOMS:
1. Native brightness controls (keyboard keys, system tray slider) do not work.
2. The global shortcuts service (kglobalacceld) appears to be inactive or broken.
3. The widget system is incomplete; standard widgets like "Command Launcher" are missing, and the "Add Widgets" list is not populated correctly.
4. The application menu does not auto-update when new .desktop files are created.

DIAGNOSTIC STEPS TAKEN:
- The `brightnessctl` command works perfectly to set the brightness, proving the underlying driver and hardware control is functional.
- The problem affects ALL users, including brand new user accounts.
- The problem persists in both "Plasma (Wayland)" and "Plasma (X11)" sessions.
- A udev rule to set permissions on `/sys/class/backlight/amdgpu_bl1` was successfully applied, but did not fix the KDE integration.
- The `acpi_backlight=none` kernel parameter was required to remove a conflicting `acpi_video0` device, but this also did not fix the KDE integration.

CONCLUSION:
The issue appears to be a fundamental bug in the KDE Plasma services as packaged in Debian Trixie, preventing them from correctly initializing or interacting with the system. It is not a user configuration error. A reliable workaround is to create manual .desktop launchers that call `brightnessctl` directly.

work.

On my systems, the system tray slider works on wayland but not on kwin.  Does
that match your experience?

It works on my system with a Ryzen 5 5500U with integrated Radeon Graphics.
Perhaps the issue you are having is specific to the 780M?

Out of curiosity, do you have the firmware-amd-graphics package installed?

I have a AMD Ryzen 7 with 780M Graphics and everything works fine. The F4
and F5 keys dim and brighten the screen. I can also adjust the brightness
via the Brightness and Color system tray widget. I am running Debian 13. If
I recall correctly Debian 12 had some issues. I have
the firmware-amd-graphics driver installed.


Out of curiosity, do you have the firmware-amd-graphics package installed?