DisplayPort monitors via HP USB-C Universal Dock not detected by HP EliteBook 840 G7

Question

I've connected the monitors to the dock, and the monitors detect when they are being connected and disconnected, so there doesn't seem to be any issue with the signal as such. All the other plugs on the dock are also working perfectly (power, Ethernet, USB to keyboard and mouse, USB-C to laptop). Basically everything is working fine, but Linux is not detecting the monitors connected to the dock.

sudo dmesg --follow does not show anything when disconnecting and reconnecting a monitor.

Should this be solvable? I'm running XWayland on GNOME on an up-to-date Arch Linux 5.10.47-1-lts.

Answer 1

What does the lsusb command say about it?

If the output line for the dock includes ID 17e9:600a, then it is this one: a DisplayLink dock.

DisplayLink docks essentially provide an extra USB-connected almost-GPU that needs its own evdi driver module. The driver package also includes firmware that is needed for the USB-GPU to work, a libevdi library, and a closed-source DisplayLink Manager application.

You could get the firmware and the application by extracting the driver package and then build the driver and library from sources available on GitHub.

The ArchWiki also seems to have advice on using DisplayLink devices on Arch. As far as I've understood, the procedure should be essentially the same as with the USB-3.0 DisplayLink devices, although your dock uses the newer USB-C connection.