this post was submitted on 06 Sep 2023
11 points (92.3% liked)

KDE

5322 readers
108 users here now

KDE is an international technology team creating user-friendly free and open source software for desktop and portable computing. KDE’s software runs on GNU/Linux, BSD and other operating systems, including Windows.

Plasma 6 Bugs

If you encounter a bug, proceed to https://bugs.kde.org/, check whether it has been reported.

If it hasn't, report it yourself.

PLEASE THINK CAREFULLY BEFORE POSTING HERE.

Developers do not look for reports on social media, so they will not see it and all it does is clutter up the feed.

founded 1 year ago
MODERATORS
 

Hi all.

Happy KDE Plasma user for a long time and I generally love the desktop experience. But I do have one small issue.

At work, I have 2x 4K displays. connected through a Dock. But in Plasma it's only able to give me around 1080p resolution on both of them. In contrast, the display manager SDDM and TTY displays 4k on each fine.

So am I missing a trick to get the max resolution in Plasma? My install is Arch Linux, kernel 6.4.12, Plasma 5.27, Wayland session.

I did install the displaylink AUR package, as I thought it might be the dock limiting the video output, but it isn't as TTY and SDDM seems to display it correctly.

Happy to hear any thoughts and any ideas. :)

EDIT: The screens turn on and work fine with 4K resolutions in a Plasma X11 session.

you are viewing a single comment's thread
view the rest of the comments
[–] Strit@lemmy.linuxuserspace.show 1 points 1 year ago (1 children)

I can select up to 2160p in the settings, but the screens just turn black until the settings reset, if I do. The highest resolution where the displays both turn on is 1080p. If I set them to 1440p only 1 of them turns on.

[–] Zamundaaa@discuss.tchncs.de 4 points 1 year ago (1 children)

Okay, sounds like a bandwidth related issue. Could you try putting KWIN_DRM_PREFER_COLOR_DEPTH=24 into /etc/environment and rebooting?

[–] Strit@lemmy.linuxuserspace.show 1 points 1 year ago (1 children)

This worked for me. Thank you very much. I'm now running 2x 4K screens on Plasma wayland.

What is the default color depth set to? 32?

[–] Zamundaaa@discuss.tchncs.de 4 points 1 year ago* (last edited 1 year ago) (1 children)

The default is 30. Drivers are supposed to limit the bit depth automatically to make the display work, but DisplayLink is quite shitty so I guess I should not be too surprised. I think I'll just make KWin force it to 24 for DisplayLink by default to get rid of the problem for everyone

Edit: heh, I already effectively did. It should not happen in Plasma 6 anymore

That's awesome. Thank you for all your work!