port-amd64/57529: Keyboard gets stuck in installer

[mneumann%ntecs.de@localhost]

>Number:         57529
>Category:       port-amd64
>Synopsis:       Keyboard gets stuck in installer
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    port-amd64-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Jul 17 08:35:00 +0000 2023
>Originator:     Michael Neumann
>Release:        10.0-BETA
>Organization:
>Environment:
10.0-BETA
>Description:
Trying to install NetBSD 10.0-BETA on Tuxedo laptop with USB stick.

Keyboard works normally within the installer. When executing "Utility menu" -> "Run /bin/sh", within the shell, the keyboard soon either gets stuck completely (pressing any key has no effect) or keeps on repeating the last typed letter infinitively.

Note that the kernel is still operational. Unplugging the USB stick shows a "green" message, plugging it in again also. Also pressing the power off button still works.

I can exploit this bug reproducibly.

Maybe worth noting: 

- Also tried OpenBSD 7.3 on same hardware. Same issue with installer.

- FreeBSD works fine. DragonFlyBSD also has no issues with the keyboard (if I remember correctly).

- Touchpad (psm0) on FreeBSD sometimes get stuck for a second as it looses sync. I wonder if this might be related to keyboard issues...
 
  https://gitweb.dragonflybsd.org/dragonfly.git/commit/7e948aa0faea67491a7cf443136aa7ce895f3953

- I wonder if PR 57492 is related.
  http://gnats.netbsd.org/cgi-bin/query-pr-single.pl?number=57492

- Note, I also tried NetBSD 8.0 and 9.0. They won't boot at all, failing with a panic "cnopen: no console device". 

- At least one time, booting stopped with a message "i915drmkms0: notice: Failed to load DMC firmware i915/kbl_dmc_ver1_04.bin. Disabling power management." (Unsure which NetBSD version that was...)

- Sometimes when the keyboard was get "stuck" it happened to be paired with a "acpibat0: normal capacity on `charge state'` message. Maybe just a coincidence...

- I made a couple of videos of the problem... if it's worth :)
>How-To-Repeat:
Boot NetBSD installer 10.0-BETA on my Tuxedo laptop with USB stick. Within the installer, execute "Utility menu", then "Run /bin/sh". Now type a bit and after a couple of seconds the keyboard should either get stuck or keeps repeating. 
>Fix: