U2422HE, U2417H, KVM, daisy chain

@Yongins  You're correct that you can't use a daisy chain if you're connecting to the first display in the chain through HDMI.  The setup you're attempting should work just fine.  Out of curiosity, if you simply disconnect the USB-C1 (90W PD) cable and have only your Mini PC connected via DisplayPort and USB-C2 (data-only), and then associate the DP input and USB-C2 with each other, do the daisy chain and USB connectivity both work?  If so, if you reconnect your laptop to USB-C1 (90W PD), does that immediately cause the Mini PC's functionality to break?  If not, what happens if you switch the display to USB-C1 and then back to DP?

Thanks for the reply was actually awaiting responses here but it seems I missed being notified.  "only your Mini PC connected via DisplayPort and USB-C2 (data-only), and then associate the DP input and USB-C2 with each other, do the daisy chain and USB connectivity both work? "  This was the method I was hoping would work but I get no signal display input on the primary Dell U2422HE in this setup and also no daisy chain.  I sense the USB-C2 gets detected as I can hear the mini PC detecting USB plug and play but the issue is I have no signal display via the DP input port on the primary monitor.  The only thing I have not tried here is my DP cable, as my mini PC uses a Mini Display port to DP cable am not sure if the issue is on that cable.  e.g does it need to be DP 1.4 capable? I believe the cable came from my Intel NUC and it should be DP1.2 capable though.  The other thing is that on the OSD - USB menu I only see assignment for DP Input and HDMI and no USB C input so this is why I was checking whether it the USB-C input port and DP Input port is shared on this monitor.   So in the setup I tried, I had to set DP Input and HDMI to USB C2 for example but this setup still results in no input signal on the primary monitor like I mentioned.  Having DP Input to USB C1 with PD works all the time with Daisy chain but that said as this is the only method that works for me, I have to disconnect this USB C1 cable to switch back and forth my PC and Laptop which is not ideal.  I purposely got the monitor hoping I can make use of the KVM.  Thanks. Hope for some advise 

@Yongins  The cable wouldn't have to be DP 1.4 since even DP 1.2 can handle twice as much bandwidth as you need for this daisy chain.  But I suppose the cable could simply be bad.

I'm not surprised you don't see an assignment option for USB-C1 since any system that could use that as a display input would also be able to use it as a USB data path, so it wouldn't make sense to use it only for video, nor would it make sense to use it only for USB given that you have USB-C2 available for that purpose.

Don't assign both DP and HDMI to USB-C2 if you're not actually using HDMI, which you shouldn't be anyway since it won't allow a daisy chain.

It's not clear from your response whether you tested all of the scenarios I asked about above.  It sounds like you've confirmed that if you disconnect USB-C1, you can use DP+USB-C2 -- is that correct?  If so, what happens when you reconnect USB-C1?  Does that immediately break the DP input?  If not, when does it break?  After you actually switch to USB-C1 and then back?

@jphughan Thanks, I just tried again today and managed to get the DP input to work with USB-C2.  Initially I used the single USB C1 with PD on the mini PC and I disconnected it and now tried with DP input and USB-C2.  It worked and I have daisy chain and the mini PC is now on the DP input with USB C2 for data.

Issue is when I now add the laptop to use the USB C1 single cable with PD, I get no display input on the monitor.  No daisy chain as well since primary monitor can't detect the signal.  I can sense it can detect USB devices attached on the monitor but I get no display.  So I can't seem to get video inputs to work on each device with USB C1 and DP input.

On OSD I have DP input to USB C2 and HDMI to USB C1

I've done some additional tests, it looks like DP input and USB C1 port can't be use at the same time which is a bummer. 

Can you help confirm if I can use USB C1 port and DP input port at the same time for each machine?  Or I can use it only one at a time?  Is this related to USB C DP alt mode?

I've check the manual again and it seems to show Video Input as only USB C port and HDMI. it does not seem to show DP input as another video input source.  Now i have it setup with HDMI on the mini PC (no MST) and USB C1 with PD on the laptop which has MST.  Whenever I use DP input and USB C1 at the same time I can't get them to work at the same time for each machine.

@Yongins  Unfortunately I don’t have a 2022 model year U Series display to test with myself. If it’s truly not possible to connect DP and USB-C and switch between them, I agree that would seem to be an unintuitive and frustrating limitation, and I’m not sure what would be causing that. But if that’s the case and you still want to keep the display, the only alternative I can think of here would be to connect the desktop directly to both displays rather than relying on daisy chaining. But this of course means you’ll need to manually change the input on your second display as well whenever you switch systems. Although it does also mean you’d be able to run with each system using one display if that might ever be useful to you, which wouldn’t have been possible before. Sorry I don’t have a better answer!

@jphughan I finally managed to get DPinput and USB C1 to work simultaneously for each device.  It seems the order of connecting the cables seems to have an effect on the setup.  I already tested the each work with its own inputs and finally managed to get them to work simultaneously, what did the trick was unplugging the USB C2 cable it seems when I get no input display scenario and just having that trigger again though am still not sure but in any case am just happy its resolved.  Thanks for all the assistance.  For the rest I can confirm that Dell U2422HE would work with USB C1 with PD and DP input with USB C2 data cable for KVM and with Daisy Chain.  Happy camper now

@Yongins  Excellent! Thanks for reporting back. Not sure why that extra effort was necessary, but glad it worked and that you posted the solution in case it benefits others who might encounter this.

Reviving this thread, as I've a related challenge to optimize my setup involving Daisy chain and KVM: 

Laptop1 connected to Monitor1 & Monitor2 (Daisy chained using DP).                                                                        (Mostly project on Monitor1 ; at times, need to use both)
Laptop2 connected to Monitor2 through USB-C for PD and display.

Question is -

How can use the Monitor's KVM feature - does KVM work on the Daisy connection(using DP) ?

Hi @Harsh331 , did you find any solution?