Arch Linux

databending

Member

Registered: 2021-10-06

Posts: 1

Issues with thunderbolt 3 external monitors

Hello everyone!

I am running an Lenovo Thinkpad X1 extreme Gen2 with a thinkpad dock. On the dock, I have two monitors connected over display port. Currently using bumblebee and Gnome, I am experiencing a lot of inconsistencies when trying to connect my laptop to the external monitors. Sometimes, doing a simple "optirun intel-virtual-ouput" does the trick and both monitors receive an output. Other times, only one monitor receives an output, to fix it, I need to do a bit of hacking (disabling, and enabling the monitors in display settings until finally it starts working while running "optirun intel-virtual-ouput"). Overall, it is very inconsistent and there is no straight forward solution but to play around with the hack until it finally works. Funny enough, I am able to detect the displays, and even when gnome is telling me that the displays are enabled, sometimes there is still no output provided. Any ideas/suggestions to fix this odd behavior, has anyone else also experienced this? I've been following the arch wiki until this point so I believe I have been doing everything properly! Thanks for the help!

Last edited by databending (2021-10-06 17:11:24)

ruffy

Member

Registered: 2017-06-10

Posts: 71

Re: Issues with thunderbolt 3 external monitors

On which resolution do you run these two monitors?
Which Thinkpad dock do you have? Ultra?

EDIT: Oh sorry my bad, there is only one thunderbolt 3 dock.

Did you try reducing the resolution? I had the same issue as the USB-C and Thunderbolt docks does not support arbitrary resolutions for the connected monitors

Last edited by ruffy (2021-10-08 07:43:06)

fistrosan

Member

Registered: 2020-04-01

Posts: 171

Re: Issues with thunderbolt 3 external monitors

With Lenovo and Thunderbolt 3 docking station it is always a good idea to make sure first that you have the latest available firmware. It has happened to me in the past that external monitors connected via display port to the docking station are not even recognized. What is the output of:

fwupdmgr refresh --force
fwupdmgr get-updates

If the external monitors are already recognized you might want to install arandr with pacman and see if you can change resolutions using arandr's gui. It is pretty handy I have found.