SUMMARY Visual artifacts (randomly coloured squares) appear on plasma things whenever there is a change of pixels. STEPS TO REPRODUCE 1. Startup PC 2. Observe the intro screen glitching wildly OBSERVED RESULT Randomly coloured squares appear in (presumably) plasma administered things like the intro screen, the task bar, the settings application, the system monitor application, the fade to black of the sleep mode or the desktop whenever I am causing a rapid change in overall pixels being displayed by for example moving the mouse or a window, however the change of pixels can be in a totally different application. EXPECTED RESULT No colourful squares =D SOFTWARE/OS VERSIONS Linux/KDE Plasma: Nobara 40 (based on Fedora) KDE Plasma Version: 6.3.0 KDE Frameworks Version: 6.11.0 Qt Version: 6.8.2 ADDITIONAL INFORMATION So far only observed on a Lenovo IdeaPad 5 16AHP9 Also please forgive me, for I am far from understanding any part of linux even remotely.
In the "Display configuration", do you have the "Color accuracy" set to "Prefer color accuracy"? Because if you do, the this might be a duplicate of: https://bugs.kde.org/show_bug.cgi?id=499935 Or: https://bugs.kde.org/show_bug.cgi?id=500477 Or: https://bugs.kde.org/show_bug.cgi?id=500712
Created attachment 178855 [details] Video of the bug
Also no, I am not using "prefer colour accuracy" nor "blur". However, as can be seen on the video, it now also with other application, it didnt do that before updating.
I also wasnt able to capture it with spectacle, however i was able to capture it with OBS (tho it didnt have the task bar on it, and I didnt wish to go through some setting to maybe include it) Also I am aware that one may identify me through the means given in here, if sb wishes to waste their time doing so, feel free.
What graphics card are you using?
(In reply to samuelboehringer06 from comment #3) > Also no, I am not using "prefer colour accuracy" nor "blur". > However, as can be seen on the video, it now also with other application, it > didnt do that before updating. Wow, there are a lot of glitches! I had some in the past like horizontal lines, by nothing so many and severe. I have no idea, besides thinking that it must be a GPU driver problem. Maybe the updates were not for KDE software only or interacted with KDE software in a bad way. Can you boot KDE Neon testing and unstable editions in live mode from a USB pen drive and see if you still have the same problem? I'm curios if this is Kwin problem or a distro problem, as the GPU driver problem is already the most suspected one.
So, no artifacts on Neon from pen drive. The GPU in this thing is the integrated 780m. I had some slight gliches on the system in the past, but after the last update it started going wild and that's why I decided to file this report in the first place. Now I also just realized (whilst going through some code rather quickly) that if I just change things within the window (scroll through some code in a IDE) ONLY the task bar gliches, that is what lead me to believe it being plasmas fault in the first place. I also suspected it to be something with the driver, but then again, why would it not happen inside the IDE when scrolling through code. Also sorry for both my slow reaction time and bad spelling as well my lack of technical knowledge
This looks like it'll likely be a GPU driver bug of some sort. These AMD integrated GPUs have had a lot of them recently. I'll let the KWin folks make that call though.
Well I thought it be the drivers too, but why would it only glich things when using plasma stuff, like if I scroll through some code in VSCode it does not do anything, only if i just used a plasma thing, like switching applications or opening the application menu, only then when scrolling does the taksbar (and ONLY the taskbar glich). Now when I scroll through some code whilst using nvim in 'Konsole' there is artifaction even outside of the taskbar (since applications are in fullscreen mode in both cases they are the only other thing on the screen) Even tho I have no idea about any of this, it kinda feels like what I would assume something with some kind of graphics buffer. Since the distro I am using uses a slightly altered kernel, that my be a source of problems. Also on pen-drive-neon it did not glich, which i would assume it would if it would be driver related.
And I've got some more infos: The artifacting seems to sometimes display whatever application is behind the current application, this specificly happens a bunch in 'Konsole' Arent the drivers in the kernel or something? / how would I go about updating drivers? Is there some other setting that makes something like the terminal transparent? Could this have something to do with the window manager? (idk just thought this might something-isch)
Since Kwin unfortunately doesn't have a easy way to print or even log the output, maybe you can try to look at systemd's log, in live mode, with this command: sudo journalctl -f Then try to trigger the bug(s) / artifact(s) as usual! Then press CTRL+C to stopp the live log seeing of journalctl. I have no idea if this suggestion is useful or not, but maybe you can see something obvious in that log, like with red or yellow colors. Or with words like: error, fatal, crash, etc.
All right, I may or may not have found the culprit. So reverting back to kernel 6.11.9-200 did solve the issue, so this might just be a driver issue (as far as I understand amd drivers are in the kernel?), if not then something else must have changed from 11 to 12 (confirmed buggy version is 6.12.11-204) that might lead to the glitches (perhaps something with the rendering of windows, particularly that perhaps non see through ones might be handled as transparent??) On a side note, the performance on the newer kernel also seems to be abysmal (nothing runes smoothly) I'll leave this issue open for now if noone objects, for I do still believe it to be a point of concern. (Perhaps the kernel change something plasma now uses incorrectly?? idk)
(In reply to John from comment #11) > sudo journalctl -f > Then try to trigger the bug(s) / artifact(s) as usual! (back on kernel 6.12) So, I tried that and I cannot see anything that I would directly relate to the issue. The only thing is that if I move a window very quickly (one way to induce the error) it does give me: >kwin_scene_opengl: 0x2: GL_INVALID_OPPERATION in glDrawBuffers (unsupported buffer GL_BACK_LEFT) However this does not come up when using other methods (like just scrolling through a man page) which does result in glitches just as strong or stronger then moving windows. Also the same error message appears (sometimes) on my main PC with the same distro and kernel (6.12.11-204) when moving the mouse rather quickly however (obviously) without the visual artifacts. So I'd assume this can be ruled out. From this i would gather that the kernel intern drivers are in fact the problem, hence if noone else wishes to add anything, I'll close this issue in a few days. Also thanks to everyone who has been using their precious time for my benefit, u guys are awesome.
Because the glitches affect app windows, the issue can't possibly be in Plasma because Plasma isn't responsible for drawing app windows. Moving back to KWin.
So, now knowing that is has to be something about the kernel 6.12 I was able to find this: https://bbs.archlinux.org/viewtopic.php?id=301280 Through that it seems it is indeed some kernel problem, not at all related to plasma or KWin for GNOME users had the same issue, it seems.