SUMMARY The percentage of brightness slider does not sync with OSD settings. There are few modes in my monitor OSD settings like normal, low-blue. Each mode has its own brightness. When I switch one mode to another, the percentage of brightness slider in panel widget is not synced with that. STEPS TO REPRODUCE Here is the screen record of the situation: https://youtu.be/S8n0m8F9iJI OBSERVED RESULT The brightness slider does not sync with OSD settings. EXPECTED RESULT The percentage of brightness slider is same as OSD settings SOFTWARE/OS VERSIONS Operating System: Arch Linux KDE Plasma Version: 6.3.2 KDE Frameworks Version: 6.11.0 Qt Version: 6.8.2 Kernel Version: 6.6.72-x64v3-xanmod1-1-lts (64-bit) Graphics Platform: Wayland Processors: 16 × AMD Ryzen 7 5800H with Radeon Graphics Memory: 13.5 GiB of RAM Graphics Processor: AMD Radeon Graphics ADDITIONAL INFORMATION
Possibly a DDC issue for not sending change events? Or possibly our issue for not listening to or reacting to them, if it does send them. Needs someone with relevant knowledge and hardware to investigate.
I found a similar bug report: https://bugs.kde.org/show_bug.cgi?id=470106. But if so, the bug should have been fixed.
Similar problem on a DELL P2723DE. Was set to 25% brightness on OSD but KDE see it at 100%. I can change the OSD value from Linux with ddcui that report the correct brightness value. The screen is connected via HDMI. SOFTWARE/OS VERSIONS Operating System: Kubuntu 25.10 KDE Plasma Version: 6.4.5 KDE Frameworks Version: 6.17.0 Qt Version: 6.9.2 Kernel Version: 6.17.0-6-generic (64-bit) Graphics Platform: Wayland Processors: 16 × AMD Ryzen 7 5800H with Radeon Graphics Memory: 32 GiB of RAM Graphics Processor 1 : AMD Radeon Graphics Graphics Processor 2 : NVIDIA GeForce RTX 3070 Laptop GPU
Created attachment 186388 [details] Visual presentation of mismatched brigthness value