LG UltraFine 5K Frequent Connection Drop-off and Resets
I have an 11th Gen Intel Laptop (Framework) connected via a 0.8m Apple Thunderbolt 3 USB-C cable to an LG UltraFine 5K tiled display. Upon connection, almost every time, the monitor comes on and off multiple times in quick successions while eventually settling after a good 10-20 seconds. Once settled, it's either on and configured correctly for its native 5K resolution (as configured under my Wayland settings), or it's off, while the Wayland display manager reports it being configured for a single tile (half horizontal, full vertical resolution). The connect/disconnect fits also happens at random times even after a full working connection, after which it behaves as if it had just been plugged in.
The issue happens with 4K non-tiled resolution as well.
I've looked at the kernel logs and I see that it's constantly resetting the connection, both on the Display Port side as well as USB hubs. The cable I'm using has been used with this monitor for many months with a Macbook with no issues. I've also tested my current setup with Windows 10 and everything is fine there too. This tells me that the laptop's firmware is not the issue and neither is any of the hardware.
EDIT: I have one test case with 100% reproducability:
- Reboot with cable plugged in.
- Open chromium and navigate to a 4k 60fps content on youtube.
- Maximize the window.
At this point, the monitor loses the picture and it goes into the back and fourth trying to re-establish the link and from then on, I lose the USB connection to the monitor's hub and inability to keep a stable connection until I restart. Note that I can watch this content on my laptop's display with no issues.
I've provided more details below.
- System architecture:
x86_64
- Kernel version:
5.19.0-rc3-1-drm-tip-git-gab3bfa333f25
(ab3bfa333f25d26bb8bf414419f9a2e6a46a141f
) - Linux distribution:
Arch Linux
- Motherboard model: dmidecode.log
- Display connector:
Thunderbolt 3
- Full dmesg with debug: dmesg_after_settling_on_one_tile.log, dmesg_after_settling_on_correct_resolution.log
- Intel reg dump: intel_reg_dump.log, intel_reg_dump_after_settling_on_correct_resolution.log
- Related issue on Framework community forum.