[SOLVED] Display Wakeup from Sleep

[Lendari]

Allright so I have two Dell S2716DG monitors connected via DisplayPort to an Aten CS1942DP KVM. On one side of the KVM I have a desktop PC with an NVidia GTX 1080 Ti. This all works flawlessly once I follow the instructions to disable the G-Sync chip in the monitor from going to sleep.

On the other side of the KVM is a laptop connected through a TB3DK2DPPD native thunderbolt 3 docking station. I have tried connecting two different laptops here (A Dell Latitude 7300 running Windows and a McBook Pro 2020 running OSX) and both have the same issue. When the laptop goes to sleep, the monitors do not reliably wake up like they do with the desktop. Usually neither comes on, sometimes one comes on, it's very unpredictable. I can't wake the monitors up by powering them off and on again, but they will wake up if I disconnect and reconnect the thunderbolt cable to the dock, or reboot the laptop.

Since the problem consistently occurs with 2 different laptops running different operating systems makes me think there's still some hardware issue. Perhaps something related to PCI-E power settings that would generally be turned on for a laptop but not for a desktop? Anyone got an idea what's going on here?

 

[SteveRX4]

There;'s also a few software KVMs that you could try - https://www.makeuseof.com/tag/why-you-no-longer-need-a-kvm-switch-for-your-multi-pc-setup/

Have you set power and sleep the same on the PC as the laptops?

 

[Lendari]

So I looked at those software KVM's and they have serious limitations around sharing a video device. For example, one of them only shares the keyboard/mouse and requires each machine to have fixed video displays. This is useless unless you want like 4 screens on your desk and only able to use 2 at a time. The others essentially create a remote desktop connection from one computer to the other. I actually started this whole thing by RDPing from one computer to the other but the video quality was so poor I decided I needed something better. Hence the KVMs supporting DisplayPort and the TB3 dock allow for a fully native 1440p @ 144Hz signal from end-to-end from either machine.

I almost want to write the author of that article a reply about why yo DO still need a hardware KVM.

Anyways, setting the power and sleep on a laptop to be the same as a desktop is a tricky task since laptops have a lot of settings that just don't apply to a desktop. Settings that go deep into the proprietary drivers and BIOS of the device. This is especially true when one machine runs OSX and the other runs Windows. What I need is to narrow the behavior down to the settings that are likely to interfere with this behavior as perfect alignment is probably impossible. Modern laptops are incredibly dependent on power saving hacks to manage battery life and heat and just mass disabling every possible power saving feature is a really bad idea. For example, turning off the sleep entirely "fixes" the problem, but running a laptop 24x7 without sleeping will almost certainly shorten the life of the battery and other components. They just aren't designed for that.

 

[SteveRX4]

There will be settings in bios. And settings in Windows. I gather there are equivalent settings in OSX.

I think trying to use a KVM between such differences is fraught with bad possibilities. If it was me, I like the simple life, so I'd keep the two devices separate. We get enough problems here with much more simple systems.