Displays freeze up intermitently when DisplayPort MST hub is connected
Brief summary of the problem:
I have a RX6700XT and 5 displays, however the video card has only 1 HDMI output and 3 DP outputs, to fix this problem, I acquired a DisplayPort MST hub and connected 4 of them to the hub, then the hub to one of the DP outputs in the video card, and the "main" monitor to the HDMI output in the video card. While erratic (sometimes I had to turn a monitor on/off for it to pickup), it worked fine, all monitors worked as they should. However in the last day or two, it stopped working completely, before that it worked fine, for months.
To test it, I unplugged the MST hub, doing so unfroze the HDMI display, I tried connecting the hub back again, and it froze once more. Note that while it freezes, it does so for a few seconds, then comes back for another handful of seconds, then freezes again and keeps doing that forever, until I either disconnect the MST hub or it "stabilises" and keeps running fine with however many monitors it managed to get online. At first I thought it was a problem with having multiple monitors, but if I connect them to the video card directly, it works fine. I can't really tell, but it seems that the computer actually keeps running fine in the background, but with all the displays completely frozen.
In one of the times I rebooted, it managed to pick up all the monitors connected through the hub, however one of them was reported as "unknown display" by gnome and supported only very low resolutions, I tried to turn it off/on, but it didn't come back. Oddly enough, it struggled to "stabilise", but when it did it kept running just fine.
Hardware description:
- CPU: AMD Ryzen 9 5950X
- GPU: AMD RX 6700XT
- System Memory: 64GB
- Display(s):
- one LG OLED48C1AUB
- four Philips 242V8A
- Type of Display Connection:
- the one LG is connected directly in the HDMI output of the video card
- the four Philips are all connected to the MST hub, which is connected to one of the DP outputs of the video card
- the DisplayPort MST hub, Tripp Lite B156-004-V2
System information:
- Distro name and Version: NixOS 23.11.20230906.0bffda1 (Tapir)
- Kernel version: 6.1.51
- Custom kernel: N/A
- AMD official driver version: unsure what "official" means, Mesa 23.1.5 (?)
How to reproduce the issue:
- Have a DisplayPort MST hub plugged in, boot the computer; or
- While the computer is already running, plug a DisplayPort MST hub in.
Attached files:
- dmesg-output, for context: in this dmesg output, I also unplugged the hub and tried connecting one of the DP monitors directly to the video card.