SUMMARY No KScreen configs present, no video output in Plasma 6. STEPS TO REPRODUCE 1. Installing Kubuntu 25.04. 2. Using video outputs from iGPU of Ryzen 5 7600 and dGPU which is RX 580 2048SP. OBSERVED RESULT No KScreen configs, Plasma cannot display video without nomodeset and without being locked at 60Hz. EXPECTED RESULT KScreen configs in user's ./local/share/kscreen present, Plasma can display video from both outputs at the monitor's maximum refresh rate. The result is as expected on Kubuntu 24.04 with Plasma 5. SOFTWARE/OS VERSIONS Linux/KDE Plasma: Kubuntu 25.04, Plasma 6.
Is this happening on X11, Wayland, or both?
(In reply to Nate Graham from comment #1) > Is this happening on X11, Wayland, or both? Sorry for the delay, I have more details now: Originally it was happening on Wayland. On Wayland the iGPU output does not work. Monitor recognises an input, but "can not support" it, meanwhile on dGPU the output was completely black, but that could have been a BIOS issue or something similar, as seemingly I am able to get dGPU output now, but only in the OS and not on the login screen (which seems to be iGPU@60Hz). Focusing on the in-OS iGPU output now, it seems like Plasma Wayland was trying to default to 180Hz (my monitor's refresh rate) and was unable to handle that for some reason. Using nomodeset forces it to use 60hz, but having nomodeset on all the time is not a great solution. On X11, it is possible to get video out from the iGPU immediately, without nomodeset, because it seemingly defaults to 60Hz, at least in my experience, however, I am not sure if that's simply because I've had it set to 60hz on Wayland and then switched over to X11. High refresh rate output from the iGPU is broken on both Wayland and X11 in Kubuntu 25, which is not the case in Kubuntu 24. dGPU now works inside the OS, but not on the login screen. Additionally, I have done some testing on a live cd / installer environment. While the iGPU video output does not work in-GUI (probably because it defaults to a high refresh rate, which is broken, as previously stated), I was able to get into a TTY, which is visible on the iGPU. From that I was able to get an error message: [ 355.263209] amdgpu 00:10:00.0: [drm] *ERROR* lttpr_caps phy_repeater_cnt is 0x0, forcing it to 0x80.
Thinking about it, maybe the origin of this issue is amdgpu, not KScreen?
Quite possible. Moving to KWin for further inspection
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🐛🧹 This bug has been in NEEDSINFO status with no change for at least 30 days. Closing as RESOLVED WORKSFORME.
(In reply to Bug Janitor Service from comment #6) > 🐛🧹 This bug has been in NEEDSINFO status with no change for at least 30 > days. Closing as RESOLVED WORKSFORME. No one told me what info is needed
I have been unable to reproduce the KScreen config issues, but I have been able to reproduce the iGPU unsupported video mode issue
Cool. Can you open a new bug report for just that issue?