kern/58019: xhci causing occasional kernel panic/reboot (kassert failing)

[netbsd%acc.zubko.cc@localhost]

>Number:         58019
>Category:       kern
>Synopsis:       xhci causing occasional kernel panic/reboot (kassert failing)
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Mar 09 19:40:00 +0000 2024
>Originator:     vazub
>Release:        10.99.10
>Organization:
>Environment:
NetBSD zeronet.fritz.box 10.99.10 NetBSD 10.99.10 (DEBUG) #1: Fri Mar  8 08:18:21 CET 2024  vazub%zeronet.fritz.box@localhost:/home/vazub/obj/sys/arch/amd64/compile/DEBUG amd64
>Description:
Built amd64 custom kernel with debug options enabled, based off the recent current commit https://github.com/NetBSD/src/commit/7dff59c837a6f54d67df414ee1934babf21ac4e1

Was running Firefox under X (wsfb, Xfce4) with some heavy load - multiple tabs open, YouTube playing music, opening MSTeams in another tab etc. At some point the system froze and after a while restarted, producing a crash dump on next login and printing the following error:

"Mar 9 17:36:37 zeronet savecore: reboot after panic: [ 11224.427449] panic: kernel diagnostic assertion "xs->xs_xr[dci] == NULL" failed: file "/home/vazub/src/sys/dev/usb/xhci.c", line 2090"

Also, a crash dump is present and I can provide it to the person looking into the matter, but I am not sure how to attach it to this report - it is 260MB large blob.
>How-To-Repeat:
The panic occurred seemingly randomly, without any clear trigger I could assume as being the cause, aside of having system struggle under heavy load and becoming sluggish when trying to open new Firefox tabs (MSTeams).
>Fix:
-