Linux + external HDMI monitors


I just got my laptop up and running last night, but havent had any luck getting external monitors up. I have 2 different usb-c to hdmi dongles, plus one built into my hub. Nothing works. Poking around the xrandr output, I can see it recognizes 4 displayports. I think thats my clue that maybe plain ol’ hdmi is obsolete and its time to upgrade to displayport/usb-c monitors…Although if that were true, why would framwork sell hdmi expansion cards…?

Any thoughts?

Linux can be a bit iffy with external monitors, HDMI is not an outdated standard. HDMI still serves as the primary display input for cheap displays. Ideally Thunderbolt is a better way to go as you can get USB Hubs on the monitor.

It’s not iffy with the monitors per se. It’s more that configuring the monitors the way you want can sometimes be a PITA (especially if you have mixed refresh rate and mixed DPI systems).

Very much, but it’s something that’s getting worked on. It will just take time since it’s usually mostly volunteers.

What Linux distro? What kernel version?

Does the USB to HDMI dongle(s) and hub use displayLink or displayPort alt mode?

Debian 11 w/ 5.14 kernel from backports to get it to play nice with my ax wifi card.

Im not home at the moment, but I tried my sisters dell dock with dual hdmi and it worked fine. Her boyfriend gave me a hand-me-down old dell dock that has an hdmi out an a vga out…My laptop recognized the hdmi fine, so I think Im in business. Now I need to mess with systemd to recoginze the dock and adjust video settings automatically when using the dock.

Help on that would be appreciated. I think I understand what to do, but a little hand holding never hurts.

Ok! Im back home with my new dock and Im in business.

Its a dell wd15 in case anyone cares. One monitor is on hdmi and the other is on vga.

At home on the dock, my preferred setup is the laptop closed and in a vertical stand. Ive got the laptop display set to disable and the 2 monitors set up with correct left-right orientation. I know its a pretty rudimentary script to feed the correct settings into xrandr and xfce to adjust orientation and font size, etc .

I just wonder what the best trigger for switching between to 2 modes might be. the connecting/disconnecting of the dock? existance of the monitors? or just startup/shutdown?

any thoughts?