DisplayLink/SecureBoot (fix)

Basic to intermediate difficulty - Only suitable for you if you feel comfortable:

  • using the command line

There is a known issue, where SecureBoot prevents DisplayLink from working, when you install the official DisplayLink drivers on an Ubuntu version or Ubuntu-based Linux distribution, that is not officially supported. You can find the supported distributions on the Synaptic website: https://www.synaptics.com/products/displaylink-graphics/downloads

The problem is caused by DisplayLink drivers -actually, a kernel module- not being trusted by your computer, causing it to reject it for security reasons. This article explains how you can enroll a MOK (Machine Owner Key) for DisplayLink, so that your computer accepts it as a trusted.

Before you begin

You will need the mokutil and dkms tools. If these are not yet on your system, install them with: sudo apt install mokutil dkms

To check if SecureBoot is enabled, use: mokutil --sb-state
If SecureBoot is enabled, and you experience problems with DisplayLink, this knowlede base article should solve your problem.

Steps

  1. Import the MOK key by executing sudo mokutil --import /var/lib/shim-signed/mok/MOK.der and follow the instructions. you kan use any password you want; you will need this password in step 6, when enrolling the MOK key.
  2. Reboot your computer. When booting you should see the MOK Manager EFI interface. Press any key to enter it:

mok-key-1

  1. When in the MOK Manager EFI interfact, select "Enroll MOK" and hit Enter:

mok-key-2

  1. When in the ENroll MOK screen, select "Continue" and hit Enter:

mok-key-3

  1. In response to "Enroll the keys?", select "Yes" and hit Enter:

mok-key-4

  1. You will be asked for the password that you provided in step 1; fill it in and hit Enter:

mok-key-5

  1. You will be returned to the MOK manager's main screen; select "Reboot" and hit Enter:

mok-key-6

  1. After the system reboot, execute sudo dkms autoinstall command in order to build and sign evdi module by MOK.

Now DisplayLink is ready to use. The HDMI and/or DVI ports on your docking station should work. You can verify that DisplayLink is working by executing sudo dkms status or sudo systemctl status displaylink-driver.service.

Source of screenshots: DKMS project on GitHub

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