firewire panic

Does anyone still use firewire or hack on code?
I've recently tried to connect an external firewire HDD enclosure and got this:

Unread portion of the kernel message buffer:
lock order reversal:
 1st 0xfffff8002b0f2f48 sbp (sbp) _at_ /usr/src/sys/kern/kern_mutex.c:158
 2nd 0xfffff8003f86f460 CAM device lock (CAM device lock) _at_
/usr/src/sys/cam/scsi/scsi_xpt.c:2323
stack backtrace:
#0 0xffffffff8068d220 at witness_debugger+0x70
#1 0xffffffff8068cd81 at witness_checkorder+0x7a1
#2 0xffffffff8061bab8 at __mtx_lock_flags+0x98
#3 0xffffffff802b663d at scsi_scan_lun+0x11d
#4 0xffffffff802b51f7 at scsi_action+0x67
#5 0xffffffff802a756a at xpt_action+0x1a
#6 0xffffffff8047459e at sbp_cam_scan_target+0xce
#7 0xffffffff8064f856 at softclock_call_cc+0x2d6
#8 0xffffffff8064fbf7 at softclock+0x47
#9 0xffffffff80602190 at intr_event_execute_handlers+0xe0
#10 0xffffffff806029ec at ithread_execute_handlers+0x2c
#11 0xffffffff8060285b at ithread_loop+0x5b
#12 0xffffffff805ff72f at fork_exit+0xdf
#13 0xffffffff8082483e at fork_trampoline+0xe
lock order reversal:
panic: mutex sbp not owned at /usr/src/sys/dev/firewire/sbp.c:967
cpuid = 2
curthread: 0xfffff8000ada5000
stack: 0xfffffe0504ded000 - 0xfffffe0504df1000
stack pointer: 0xfffffe0504df0a00
KDB: stack backtrace:
db_trace_self_wrapper() at 0xffffffff80420bbb = db_trace_self_wrapper+0x2b/frame
0xfffffe0504df0930
kdb_backtrace() at 0xffffffff80670359 = kdb_backtrace+0x39/frame 0xfffffe0504df09e0
vpanic() at 0xffffffff8063986c = vpanic+0x14c/frame 0xfffffe0504df0a20
panic() at 0xffffffff806395b3 = panic+0x43/frame 0xfffffe0504df0a80
__mtx_assert() at 0xffffffff8061c40d = __mtx_assert+0xed/frame 0xfffffe0504df0ac0
sbp_cam_scan_lun() at 0xffffffff80474667 = sbp_cam_scan_lun+0x37/frame
0xfffffe0504df0af0
xpt_done_process() at 0xffffffff802aacfa = xpt_done_process+0x2da/frame
0xfffffe0504df0b30
xpt_done_td() at 0xffffffff802ac2e5 = xpt_done_td+0xd5/frame 0xfffffe0504df0b80
fork_exit() at 0xffffffff805ff72f = fork_exit+0xdf/frame 0xfffffe0504df0bf0
fork_trampoline() at 0xffffffff8082483e = fork_trampoline+0xe/frame
0xfffffe0504df0bf0
--- trap 0, rip = 0, rsp = 0, rbp = 0 ---
-- 
Andriy Gapon