USB kernel panic on 7.3-RELEASE amd64 during Dell PowerEdge 2950 DRAC reset

[Panagiotis Christias]

Hello,

today we decided to add a new SSL certificate in the DRAC subsystem of
one of our Dell PowerEdge 2950 III servers. During the final step of
that procedure DRAC resets itself in order to load the new
certificate. The result of DRAC's reset was a kernel panic of the
7.3-RELEASE amd64 that runs on that system.

The panic messages seem to be USB related and are available at:
http://noc.ntua.gr/~christia/2010-06-16_163545.png

The memory dump completed successfully(?) but the subsequent kgdb
backtrace failed with the following output:
# kgdb /boot/kernel/kernel /var/crash/vmcore.0
GNU gdb 6.1.1 [FreeBSD]
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "amd64-marcel-freebsd"...
Cannot access memory at address 0x0
(kgdb) bt
#0  0x0000000000000000 in ?? ()
Cannot access memory at address 0x0

uname output:
FreeBSD XXXXXX 7.3-RELEASE FreeBSD 7.3-RELEASE #0: Fri Apr  9 22:50:50
EEST 2010     root at XXXXXX:/usr/obj/usr/src/sys/CUSTOM  amd64

/usr/src/sys/amd64/conf/CUSTOM contains just:
include GENERIC
ident   CUSTOM
options ROUTETABLES=4
options IPFIREWALL
options IPFIREWALL_DEFAULT_TO_ACCEPT
options IPFIREWALL_FORWARD

Latest /var/run/dmesg.boot is available at:
http://noc.ntua.gr/~christia/dmesg.boot.2010-06-16_163545

I have not yet tried to reproduce the panic. Any advice to collect
more useful debug info is welcome.

Regards,
Panagiotis