[RESPONDED] LG 5k 27MD5KL monitor vs. Fedora 37 + 11th Gen i7-1165G7

Has anyone else out there tried plugging an LG 5k monitor into an 11th gen Framework laptop? I get very inconsistent behavior. Sometimes it goes black for a second or two repeatedly. Other times, when I plug the monitor in, it connects and disconnects rapidly (you can tell by the chiming noises and screen blanking). Sometimes it does that once or twice and then settles down.

One time, this connection / disconnection behavior would occur such that the monitor would be disconnected when I clicked play on a YouTube video, and it would reconnect when I pressed pause. I did this a half dozen times in a row, to be sure I wasn’t imagining it. Those connections and disconnections were represented in dmesg.

It’s hard to be sure, but switching USB-C ports doesn’t seem to make a difference. The passage of time and/or window position sometimes seems to matter.

Also, I don’t know which system component presents the UI that’s tied to Fn-F9, but that doesn’t seem to do anything after I select an item from the menu. The KDE system settings seem to work. Interestingly, in that screen, the LG monitor’s represented as two separate physical devices, the second with the vertical and horizontal dimensions swapped.

Hi James,

A bit to unpack here as I have some needed details, but will help how I can.

  • Distro and version? I realize KDE is the desktop, but need to be sure about the distro specifically.

  • Is this connected to a hub/dock? Or is this is a USB-C display connected to a USB-C expansion card?

  • Wayland or Xorg?

Hi Matt, thanks.

It’s Fedora 37 and Xorg. I installed KDE using dnf at some point, probably invoking dnf install @kde-desktop-environment or similar, haven’t gotten around to installing Fedora 38 yet.

The monitor’s plugged directly into a USB-C expansion card. Thunderbolt is the protocol if I’m not mistaken. The monitor has built in speakers, camera, and a USB-C hub.

Looking again, I was wrong about the second instance of the monitor in System Settings. DP-2 is 2560x2880, where DP-1 is 3840x2160. DP-2 doesn’t exist physically – I checked behind the desk and everything.

… that resolution thing makes some sense, if you consider that the correct hardware resolution is 5120 × 2880, then you imagine the monitor’s implemented as two displays, then you imagine that Linux is getting the first virtual display’s resolution wrong (but 4k is the right aspect ratio and close enough that I didn’t notice, expecting the pixels to be off while running at 125% fractional scaling…). It’s not a huge leap after that to figure monitor-side, the 4K is getting mapped to use the full panel and then the “second panel” is getting ignored. That wouldn’t help with the disconnection problem, as much as throw doubt on the likelihood of any of this being made to work at all :smiley:

(It was the first 5K Thunderbolt 3 monitor with a “custom dual DP 1.2 controller” for Mac users, Wikipedia says.)

Just in case anyone else comes across this thread, there’s already been a lot of interesting discussion of this issue, one forum category over. I missed it at first. “lg 5k” doesn’t return search results, but “5k display” does.

LG UltraFine 5K Frequent Connection Drop-off and Resets (#6265) · Issues · drm / intel · GitLab is the bug that I’ve been encountering. That thread reports the problem across both Windows and Linux, including Ubuntu on some Lenovo laptop. Doesn’t sound like it’s limited only to Framework laptops.

Lastly, if I set “both” LG “displays” to 2560x2880, then the monitor renders both of them side by side. Between KDE and Xorg, they aren’t presented as being a single display on the software side.

For now, I’ll keep tolerating it as-is until I get the right set of kernel updates and somebody forces me to use Wayland. Running it as a 4K monitor isn’t that bad, either, and it’s a smoother workflow with the fractional scaling looking alright at 125% (same as the built-in display).

Appreciate the update.