How to use DisplayLink Ubuntu driver with UEFI Secure Boot?

On a machine that has Secure Boot enabled, all 3rd party kernel modules must be digitally signed.

DisplayLink uses DKMS to build and install the evdi kernel module from sources. This is the same mechanism that many other vendors, e.g. Oracle for VirtualBox use.
Unfortunately, this means that it is not possible to use the driver and the device just after installation, because modules that are built during the process have no signature, and therefore will not be allowed to load.

Option 1: Benefit from the automatic signing by dkms package


Since Ubuntu 18.04 signing modules is handled automatically by dkms package, remember to reboot to finalize.
Please follow below procedure.

Option 2: Disable secure boot


The easiest solution is to disable Secure Boot in UEFI (BIOS) settings. After rebooting, unsigned modules will load normally.

Option 3: Sign evdi kernel module manually


Alternatively, users must sign the evdi kernel module themselves. For instructions, please refer to the askubuntu thread:
https://askubuntu.com/questions/762254/why-do-i-get-required-key-not-available-when-install-3rd-party-kernel-modules

The process of signing will have to be repeated after every kernel upgrade, or after upgrading to a newer version of DisplayLink driver.

Feedback and Knowledge Base