port-amd64/56171: Removing USB keyboard always causes panic

[vezhlys%gmail.com@localhost]

>Number:         56171
>Category:       port-amd64
>Synopsis:       Removing USB keyboard always causes panic
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    port-amd64-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri May 14 22:00:00 +0000 2021
>Originator:     Andrius V
>Release:        NetBSD 9.2
>Organization:
>Environment:
NetBSD  9.2 NetBSD 9.2 (GENERIC) #0: Wed May 12 22:13:25 EEST 2021  andriusv@:/home/andriusv/netbsd-src/sys/arch/amd64/compile/GENERIC amd64
>Description:
After building NetBSD 9.2 code, removing my Fnatic Gear Rush Pro keyboard (it also has USB hub) from USB port always causes NetBSD to crash. I believe it is some kind of regression since I don't remember that happening before, but I may try to test older kernels (and current) later if relevant. The system itself is Ryzen 5 3600 CPU on x370 chipset based computer. Mate desktop environment is used. Error log (typed manually from image, thus may contain typos):

fatal page fault in supervisor mode
trap type 6 code 0x2 rip 0xffffffff8066074c cd 0x8 rflags 0x10282 cr2 0 ilevel 0 rsp 0xffffdb8259a66e10
curlwp 0xfffffe99290d4520 pid 0.93 lowest kstack 0xffffdb8259a642c0
panic: trap
cpu4: Begin traceback...
vpanic() at netbsd:vpanic+0x160
snprintf() at netbsd:snprintf
startlwp() at netbsd:startlwp
alltraps() at netbsd:alltraps+0xbb
xhci_device_ctrl_start() at netbsd:xhci_netbsd_ctrl_start+0x282
usbd_transfer() at netbsd:usbd_transfer+0x95
usbd_do_request_len() at netbsd:usbd_do_request_len+0x99
usbd_do_request() at netbsd:usbd_do_request+0x24
usbd_clear_endpoint_stall_task() at netbsd:usbd_clear_endpoint_stall_task+0x6f
usb_task_thread() at netbsd:usb_task_thread+0x94
cpu4: End traceback...

Regards,
Andrius V
>How-To-Repeat:

>Fix: