panic: kernel diagnostic assertion "mii != NULL" failed

[Jaap Boender <jaapb%kerguelen.org@localhost>]

Hi all,

since 9.99.19, whenever I try to activate an urndis device, I get a 
kernel panic with the following message:

kernel diagnostic assertion "mii != NULL" failed: file 
"/usr/src/sys/dev/usb/usbnet.c" line 1191

The backtrace is:
_KERNEL_OPT_NARCNET() at 0
?() at ffff989b51e1f418
vpanic() at vpanic+0x181
kern_assert() at kern_assert+0x48
usbnet_tick_task() at usbnet_tick_task+0x20e
usb_task_thread() at usb_task_thread+0x47

The last kernel that does not have the problem is 9.99.18; the problem 
occurs from 9.99.19, up to and including a -current I checked out a few 
hours ago.

The problem occurs when, for example, trying to run dhcpcd -MnL urndis0.

This is on a NetBSD/amd64 system; kernel configuration is GENERIC with 
nonexistent devices (on that particular machine) removed.

best

  Jaap