Can’t use all four ports on MST hub simultaneously
Linux ssside 6.6.6-arch1-1 #1 SMP PREEMPT_DYNAMIC Mon, 11 Dec 2023 11:48:23 +0000 x86_64 GNU/Linux
I’m trying the following 4-port DisplayPort MST hub and USB-C -> DP adapter:
- https://www.startech.com/en-us/display-video-adapters/mstdp124dp
- https://www.cablematters.com/pc-1038-179-usb-c-to-displayport-adapter-8k-ready.aspx
…with four identical HDMI displays (1360x768). Up to three displays, plugged into any three ports on the hub, work perfectly, but the fourth one fails. If I run xrandr --auto
with the fourth display connected, I see this:
xrandr: Configure crtc 7 failed
X Error of failed request: BadMatch (invalid parameter attributes)
Major opcode of failed request: 140 (RANDR)
Minor opcode of failed request: 7 (RRSetScreenSize)
Serial number of failed request: 77
Current serial number in output stream: 78
All four work in Windows. It doesn’t seem to be a bandwidth issue, because if I manually specify a reduced blanking mode or switch to a much smaller resolution for each display, I’m still unable to use all of them (the messages/behavior don't change).
The computer itself is an Intel NUC11PHKi7C.
Thoughts?