I recently moved from Windows to Fedora 35, but not as a newbie. I’ve used Ubuntu, Mint, and Manjaro briefly. I have a desk setup that uses two external monitors that connect through an HDMI KVM switch. When I dock the laptop, I see video on the built-in screen and one of the external monitors. Display settings in Fedora do not show the option to detect the third screen. For reference, here is the physical connection:
Laptop → Dock → KVM → Dual monitors
Ultimately I would like to just use the dual external screens and close the lid on the laptop, but it still only shows on one of the external monitors. Is this configuration even possible on linux, or am I too optimistic?
A KVM switch selects one or the other of the outputs. I don’t think it is possible to drive 2 monitors through a kvm switch at the same time.
I also do not believe it is possible to drive 2 monitors through a single HDMI or DP port
This is why it is called a KVM switch. It allows connecting a single Keyboard + Video + Mouse to multiple machines and switches between them.
Thanks for the response. I should clarify further. The KVM is a dual monitor KVM. Each selection has two inputs coming from the source (Win, Lnx, Mac). It works perfectly from a Windows machine. I can dock my laptop with a single USB-C cable to the dock. The dock has two HDMI cables going to the KVM. The KVM has an HDMI cable going to each monitor. Like I said, I am able to get Windows and Mac to display on both monitors through that KVM. It’s only Linux that has trouble. To add more detail to my case. I am doing a dual boot of Windows 11 and Fedora on the Lenovo. Windows displays on both monitors through the KVM, but Linux only displays on one monitor. It sounds like it is a limitation of Linux, unless someone can shed some light on the issue.
We need a little more detail.
How many graphical outputs exist on the laptop? One? or Two?
You do realize (I hope) that the dock has drivers in the windows OS that do not exist in linux. The issue could easily be that the windows drivers will support the dual monitor output from the dock, but that since the drivers are not the same in linux it cannot support the dual video output.
Yes. That’s what I’m afraid of at the moment. The laptop has two usb-c video outputs, but one of them doubles as a charging port. If I use both ports for video, then I don’t have the ability to charge the laptop. I think I’m going to give it one more try and see if the interwebs have some kind of magic workaround that will allow me to correctly use the dock with linux. I’m not holding my breath but who knows, maybe somebody has encountered this and figured it out. If I can’t get it to work, then I’ll have to go back to Windows again. It seems like every time I try to migrate to Linux, the same limitation applies and I end up going back to Windows. I feel like drivers from third party vendors will always be Linux’s achilles heel.
Thank you for the suggestion. The command above shows three available kernels:
I booted into the 5.14 kernel and I’m still having the same issue. Only one of the external monitors is detected. The Intel page you linked seems to suggest that dual external monitors requires efer to systems with both Intel Xe and Xe Max graphics. The Lenovo I’m using only states that it has an Intel Xe graphics card. Everything I’m reading on this topic seems to point towards the need to use both video outputs. Lenovo Yoga i9 seems to be designed to be used with Windows so that you can operate dual external monitors with only one port.
I think the main question I have is whether or not anyone has ever been able to successfully run dual external monitor using one video output port with Linux.
I opened a ticket with the vendor, J5Create, and they confirmed that they don’t support Linux operating systems. There are no native drivers for the full functionality of the dock, so it looks like it can only support one external monitor. Hopefully someone with great coding skills and a lot of time on their hands can write the driver. Until then, it looks like Linux desktop is a no-go for my workflow. Thanks for all the suggestions in this post.