Using a DisplayLink graphics adapter in Debian 8

The Unitek USB 3.0 Docking Station is a handy tool since it allows to use several interfaces on a laptop after plugging in a single USB 3.0 cable. Most of its interfaces work out of the box on Debian 8; only the DisplayLink VGA adapter needs some additional steps in order to be operational.

Disclaimer: there are several wiki entries and discussions on this topic on the web, and it may well be that the procedure described below does not work on every machine. However, it worked for mine...

Installation of the DisplayLink driver

  1. Check the Linux kernel version. As of March 8, 2016, the DisplayLink driver is not compatible with kernels 4.0 and newer. If your Debian runs on such a kernel, install kernel version 3.16 and the corresponding headers via APT. Reboot using this kernel version.
  2. It may be helpful to select this kernel version as the default one in GRUB2. This can be done by changing the setting GRUB_DEFAULT in the file /etc/default/grub and running the command 
    update-grub
    (as root).
  3. In the directory /lib/modules/3.16.0-4-amd64/build, create a link to the Makefile: 
    ln -sf Makefile Kbuild
  4. Download the DisplayLink driver for Ubuntu from
    http://www.displaylink.com/downloads/ubuntu
  5. Unzip the driver; this creates a file called displaylink-driver-<version>.run which again contains a packed version of the driver.
  6. Unpack the driver by executing 
    displaylink-driver-<version>.run --noexec --keep
    This creates a directory called displaylink-driver-<version>
  7. Change to that directory.
  8. Modify the file displaylink-installer.sh: edit the line with 
    SYSTEMINITDAEMON=
    to be 
    SYSTEMINITDAEMON=systemd
  9. As user 'root', install the DisplayLink driver by running 
    displaylink-installer.sh install
  10. At this point, a reboot may be helpful. Make sure to reboot with kernel version 3.16.

Using the DisplayLink adapter

  1. Now, the DisplayLink adapter should be ready in principle. However, after each boot process, it must be made available to xrandr with the following command: 
    $(xrandr --listproviders | grep -q "modesetting") && xrandr --setprovideroutputsource 1 0
    It may help to store this line as a bash alias or the like.
  2. When this is done, a new display output (the one from the DisplayLink adapter) should be available e.g. in arandr.

Sources

Details