DisplayLink adapter only works immediately after driver install

Question

I have a fresh install of Ubuntu 18.04 on a Lenovo E580. Upon installing the DisplayLink driver (version 4.4), my StarTech DK30CH2DPPD USB-C dock works perfectly, passing through video to both my DisplayPort and HDMI monitors. However, if I log out and log back in, reboot, or anything, the DisplayPort monitor disappears permanently until I uninstall the driver, reboot, and re-install the driver.

• It appears the reason the HDMI monitor continues to work as that port isn't actually managed by the DisplayLink protocol, rather it's powered by the USB-C DisplayPort Alt Mode. It shows up in xrander as a DisplayPort monitor even though it's connected through HDMI.
• Ironically, when it's working, the real DisplayPort monitor shows up as a DVI monitor, which is expected as that's how all DisplayLink monitors are presented to the OS.
• When it's working, xrandr --list-providers lists 2 providers. After the monitor disappears, it only lists the Intel GPU.

I have tried numerous things, from rebooting with the dock connected, disconnected, connected but with monitors disconnected, as well as restarting dlm.service. Is there something I'm missing to make this thing reliably work?

Answer 1

I had the same problem.

I found a solution here https://github.com/DisplayLink/evdi/issues/92

Where you have to insert the following text in /etc/X11/xorg.conf.d/20-intel.conf

Section "Device"
Identifier "intel"
Driver "modesetting"
Option "kmsdev" "/dev/dri/card0"
Option "PageFlip" "off"
Option "SWCursor" "on"
Option "ShadowFB" "true"
EndSection

Section "Device"
Identifier "USB3"
BusID "USB"
Driver "modesetting"
Option "kmsdev" "/dev/dri/card1"
Option "PageFlip" "off"
Option "SWCursor" "on"
Option "ShadowFB" "true"
EndSection

Section "Device"
Identifier "USB3"
BusID "USB"
Driver "modesetting"
Option "kmsdev" "/dev/dri/card2"
Option "PageFlip" "off"
Option "SWCursor" "on"
Option "ShadowFB" "true"
EndSection

Now you don't have to uninstall & install the driver again after every logout/shutdown.