Panic during reboot on amd64 9.99.52

[Paul Goyette <paul%whooppee.com@localhost>]

With a curent built from sources updated just a few hours ago (on 
2020-03-27 at 16:13:55 UTC), I get a panic during shutdown.  The
stack trace doesn't seem to be saved, but I manually transcribed
it:

	vpanic + 0x178
	kern_assert + 0x48
	config_detach + 0x65
	mii_detach + 0x109
	wm_detach + 0xb0
	config_detach + 0xe5
	config_detach_all + 0x97
	cpu_reboot + 0x198
	sys_reboot
	sys_reboot + 0x63
	syscall + 0x299
	(syscall #208)

Unfortunately, the actual panic message had scrolled off the screen,
but it included "bad device fstate".

The only mii on my machine should be

	ihphy0 at wm0 phy 2: i217 10/100/1000 media interface, rev. 5

and is configured as

	ihphy0 at mii? phy ?

Anyone got any ideas?

For now I have reverted to my previous 9.99.46 kernel...



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