UPDATE [August 9, 2021]: It turns out DisplayLink doesn’t quite work in 21.04. See this blog posting for the latest on how to work around the remaining issue.
Thanks to Peter Boros for pointing out that Canonical and Synaptics have made the fixes necessary to make DisplayLink work with Ubuntu 21.04 without any of the fixes I’ve posted. I was unaware of this because, unfortunately, Canonical did not update any of the bugs I’ve filed about this to indicate that the issue was fixed, and Synaptics did not announce the new release of their software or update the Ubuntu download page to indicate that it’s compatible with 21.04. 🤷
If you’ve installed my fixes on your Ubuntu 21.04 box to make it work with DisplayLink, here’s what you should do to undo them:
- Download the current DisplayLink Ubuntu installer from here.
- Unzip it.
- Run “
bash displaylink-driver-*.run --noexec --keep --target dl-installer“. Do this in a persistent directory like your Desktop or something, not in
/tmp, because you’re going to need these files still after you’ve rebooted, and rebooting clears
- Make sure you’ve got a monitor plugged directly into your computer, not into your DisplayLink hub, or proceed in an SSH session into your computer from a different one.
- Switch directories to the
dl-installerdirectory and run”
sudo bash displaylink-installer.sh uninstall“.
- Download the script below as
sudo bash -e hirsute-unfix-displaylink.sh.
- Reboot and log in again.
- If you’re working directly on your computer rather than through an SSH session, make sure your keyboard and mouse are plugged directly into your computer rather than your DisplayLink hub, because you can’t install the DisplayLink driver when the hub is plugged in.
- Switch into the
dl-installerdirectory again and run “
sudo bash displaylink-installer.sh install“.
At this point DisplayLink should be working, and you can delete all of the installers and scripts that you downloaded or unpacked.
Note that this uses the
evdi shared library and kernel module shipped with the DisplayLink installer, not the ones shipped with Ubuntu.