Start DisplayLink before Login (lightdm)

jbodnar · 02-01-2024, 10:03 PM

I'm using Ubuntu Cinnamon (Ubuntu 23.10) with Lightdm. I've installed the DisplayLink Debian package and my two external monitors work just fine. They are plugged into a Dell docking station which is connected to my laptop via USB-C. But they only work after I login. The Lightdm login screen is only shown on the laptop display (which I keep closed).

I tried editing /lib/systemd/system/displaylink-driver.service to change:

Code:

After=display-manager.service

to

Code:

Before=display-manager.service

but that did not work.

I've also tried various tricks with xrandr and monitors.xml as described for Ubuntu and Lightdm but they didn't work either. My guess is that the external monitors aren't available until after DisplayLink runs and that's happening after the login screen is displayed. Is it possible to get a login screen displayed on external monitors that are made available via DisplayLink?

dunkirk · 04-08-2024, 12:06 AM

I have the same problem (Linux Mint 21.3, aka Ubuntu 22.04). I also tried moving display-manager.service up in the hope that the displaylink-driver.service would be started way before the login screen but no success.

I did notice that this behavior differed from dock to dock. It only happened on my WavLink WL-UG69PD8 Pro docking station. On the Dell UD22 docking station, at least 2 out of 4 monitors can be rendered BEFORE the login screen.

------ update ------
Same behavior on MacOS.
Basically just don't restart your computer until absolutely necessary. Sleep or suspend are fine. Displaylink driver has no problem waking up.

02-01-2024, 10:03 PM	#1
jbodnar Junior Member Join Date: Feb 2024 Posts: 1	Start DisplayLink before Login (lightdm) I'm using Ubuntu Cinnamon (Ubuntu 23.10) with Lightdm. I've installed the DisplayLink Debian package and my two external monitors work just fine. They are plugged into a Dell docking station which is connected to my laptop via USB-C. But they only work after I login. The Lightdm login screen is only shown on the laptop display (which I keep closed). I tried editing /lib/systemd/system/displaylink-driver.service to change: Code: After=display-manager.service to Code: Before=display-manager.service but that did not work. I've also tried various tricks with xrandr and monitors.xml as described for Ubuntu and Lightdm but they didn't work either. My guess is that the external monitors aren't available until after DisplayLink runs and that's happening after the login screen is displayed. Is it possible to get a login screen displayed on external monitors that are made available via DisplayLink?

04-08-2024, 12:06 AM	#2
dunkirk Junior Member Join Date: Aug 2023 Posts: 5	I have the same problem (Linux Mint 21.3, aka Ubuntu 22.04). I also tried moving display-manager.service up in the hope that the displaylink-driver.service would be started way before the login screen but no success. I did notice that this behavior differed from dock to dock. It only happened on my WavLink WL-UG69PD8 Pro docking station. On the Dell UD22 docking station, at least 2 out of 4 monitors can be rendered BEFORE the login screen. ------ update ------ Same behavior on MacOS. Basically just don't restart your computer until absolutely necessary. Sleep or suspend are fine. Displaylink driver has no problem waking up. Last edited by dunkirk; 04-08-2024 at 02:01 AM.