Modern KVM issues continued.
by Luk from LinuxQuestions.org on (#6FAFC)
Previously I've been looking for a displayport KVM that would support at least eDP 1.4, edid and USB device emulation. I found only one horribly overpriced device with bad reviews so I decided to give HDMI a go instead.
I searched everywhere and I managed to find this 4 PC KVM switch by KCEVE on amazon for $75 that claims to support USB3, 4k@60Hz HDMI2.0 and EDID emulation. I connected it to my 1 windows and 2 current linux machines via HDMI and it turns out both Linux machines have a different problem while windows works flawlesly.
As mentioned the KVM switch has EDID emulation, so when it is switched to other device the devices that are off are still getting the EDID of the main monitor preventing resolutions from being changed and desktops being messed up. This works fine in windows, but my Alma Linux 9 laptop with gnome still has its internal screen go blank for ~2s when KVM is switched to it(as if it run xrandr --auto internally). I checked that EDID stays the same, but somehow the laptop detects the disconnection/reconnection and redetects the monitors. One good thing is that despite this redetection windows present on the secondary monitor do not move, but that extra 2s delay is very annoying.
The other Linux machine is an Arch desktop running i3wm therefore it has no monitor hotplug. The very weird problem that occured is: if I switch the PC on into BIOS or I stay on the linux text console I can use the KVM normally. I can switch to other PCs and back with no problem. However, when I start Xorg and I switch away, after I switch back I get no picture... until I do either of: run xrandr --auto(which detects exact same settings), disconnect the hdmi cable and plug it again(how does this do anything without monitor hotplug detection!) or restart the KVM switch.
All my cables are HDMI 2.0 and 2.1 compatible. For now I configured a udev rule that runs xrandr --auto on the arch machine when a drm event is detected. This means I'm getting teh same 2s delay on both Linux devices while the windows one has its screen appear within 0.5s.
Has anyone got any advice how to fix this? I realise not many people use Linux on the desktop and even less people use it with KVM at 4k@60hz, but perhaps someone else does and that other person has figured that out.
I searched everywhere and I managed to find this 4 PC KVM switch by KCEVE on amazon for $75 that claims to support USB3, 4k@60Hz HDMI2.0 and EDID emulation. I connected it to my 1 windows and 2 current linux machines via HDMI and it turns out both Linux machines have a different problem while windows works flawlesly.
As mentioned the KVM switch has EDID emulation, so when it is switched to other device the devices that are off are still getting the EDID of the main monitor preventing resolutions from being changed and desktops being messed up. This works fine in windows, but my Alma Linux 9 laptop with gnome still has its internal screen go blank for ~2s when KVM is switched to it(as if it run xrandr --auto internally). I checked that EDID stays the same, but somehow the laptop detects the disconnection/reconnection and redetects the monitors. One good thing is that despite this redetection windows present on the secondary monitor do not move, but that extra 2s delay is very annoying.
The other Linux machine is an Arch desktop running i3wm therefore it has no monitor hotplug. The very weird problem that occured is: if I switch the PC on into BIOS or I stay on the linux text console I can use the KVM normally. I can switch to other PCs and back with no problem. However, when I start Xorg and I switch away, after I switch back I get no picture... until I do either of: run xrandr --auto(which detects exact same settings), disconnect the hdmi cable and plug it again(how does this do anything without monitor hotplug detection!) or restart the KVM switch.
All my cables are HDMI 2.0 and 2.1 compatible. For now I configured a udev rule that runs xrandr --auto on the arch machine when a drm event is detected. This means I'm getting teh same 2s delay on both Linux devices while the windows one has its screen appear within 0.5s.
Has anyone got any advice how to fix this? I realise not many people use Linux on the desktop and even less people use it with KVM at 4k@60hz, but perhaps someone else does and that other person has figured that out.