DisplayPort and KVM switch not working as it should

[lbg]

Hi!

This topic is closley realted to:
viewtopic.php?t=341893

However I'm using DP instead of HDMI, hence a new topic. If I should instead join the topic above, let me know.

Symptoms:
- Monitors go to sleep when switching back to my computer with Linux Mint.
- The monitors come alive when I "replug" (pull them out and instert them again) the monitor cables in the computer.

Background:
I've been running windows for years on this machine and everything has been working perfectly when talking about switching between computer using the KVM switch.
After installing Linux Mint on the exact same machine. The monitors don't get any signal when switching back to Linux Mint machine, so they go to sleep.

My Machine:
Intel Core i7
Asus Z170 mobo
Geforce GTX 1070 Cerberus

KVM:
Aten cs1944dp (dual monitor 4k 60Hz, USB3)

Monitors:
2x Samsung S27H850Q

I also have Raspberry Pi 4 connected to this KVM.
The Pi is running Raspbian, which is also a Debian based distro, but for Arm.
It handles this flawlessly.

Why can't Linux Mint handle this in the same way that Windows and Raspbian does?
As I said above, Windows worked fine with the KVM and on the exact same hardware.

What can I do to fix this?
I don't want to replug the cables all the time, I really hope there is a solution to this.

Cheers!

[SMG]

Symptoms:
- Monitors go to sleep when switching back to my computer with Linux Mint.
- The monitors come alive when I "replug" (pull them out and instert them again) the monitor cables in the computer.

Welcome to the forum, lbg.

Do you have the monitors directly connected to the computer?

Please give us information about your install by entering this command in a terminal: inxi -Fxxxrz
Click </> from the mini toolbar above the textbox where you type your reply and then place your cursor between the code markers and paste the results of the command between the code markers [code]Results[/code]. This will let us know how Mint sees your hardware.

Please also provide the output of xrandr and enclose the results within code tags.

KVM:
Aten cs1944dp (dual monitor 4k 60Hz, USB3)

I found this question Do computers remember their window positions if you switch away and back in dual monitor mode? Or is it like disconnecting a monitor where they move and the seller responded

There is no emulation on the KVM switch itself. The DisplayPort protocol itself is supposed to handle the keepalive on its own, ensuring the computers remember their window positions if you switch away and back in dual monitor mode.

This, however, requires ALL of the DisplayPort components (video sources and monitors) to also behave properly. If there are any docks, adapters, port replicators, etc., involved, it's more likely to fail and result in the monitors acting like they've been disconnected.

If there is no emulation, then it would seem the EDID is not being remembered. When you pull out the cable and re-insert it you are doing a hot-plug event to which Mint will respond. Let's see how Mint views your computer to determine what other options there might be.