Keyboard input from KVM switch not working in GRUB

I recently bought the 10G 2 computer 2 monitor KVM switch. Finally got around to setting it up, but I have found at least 1 issue so far.

I dual boot my personal laptop (the other laptop hooked up to the KVM switch is a work laptop). Because I dual boot, I boot into GRUB to select which Linux kernel I want to boot into or if I want to boot into Windows. My keyboard doesn’t seem to work in GRUB when plugged into an HID input of the KVM switch. If I take the keyboard out of the KVM switch and move it to the computer directly, GRUB input works again.

Any ideas? Is this a known problem? Are there any workarounds?

Try unplugging from the kvm then plug back into the kvm. Bet that also fixes it? If so make sure nkey rollover is disabled or use a usb3 port for the kb to experiment further

The USB3 ports worked just fine. I don’t know what nkey rollover is. Plugging into one of the HID ports while in the GRUB menu didn’t help. Right now I have a headset and camera plugged into both the USB3 ports, so no open ports to plug into. Could I get a USB hub to plug into one of the USB3 slots to expand the capacity? Not sure how much the KVM switch can handle.

Hub should work fine in a usb3 port. What keyboard?

My exact model is an HP KU-1156 Assy P/N 672647-003.

Nothing special about it (that I know of). Just a bog-standard wired keyboard.

PS. Is there any way to get emails when responses are made to posts I am active in? Didn’t see anything in the preferences section. Sorry it took 3 days to respond, but I have to manually remember to come check the forum :).

PPS. Finally found the switch to flick for getting email reminders. Yay!

Hey Wendell,

Just wanted to follow up to see if you had given this issue any more thought.

I hadn’t been able to reproduce it. I dont have the exact keyboard but I have a cheapie HP oem keyboard and it seems to work okay in both USB and hid ports at the boot screenusve you tried other USB3 ports on the host?

You gave me a great idea. Between the last time we talked and now, I finally got my second laptop in for use in the KVM switch.

On my old laptop from ~2017 (ThinkPad T470P with an old style Lenovo dock), I couldn’t even get my keyboard (plugged into any of the HID ports) to enter the BIOS menu, let alone the GRUB menu. I then went to my new laptop, and tried to enter the BIOS menu, and the keyboard worked.

This leads me to believe that the firmware on the laptop or the dock might be having the issue. Luckily I have a Framework laptop coming in Q4 this year to replace that old one, so I don’t have to live with these pains much more.

Consider this issue closed :). Appreciate your help.