I've got a ServerWorks-based Fujitsu-Siemens Xeon box. At 'halt -p'

(with or without acpi) the following happens (no panic).
Any suggestions?
# halt -p

/etc/rc.shutdown in progress...

/etc/rc.shutdown complete.

sycing disks... done

Stopped at      gettick+0xec:   inb     $0x40,%al

ddb> tr

gettick(d116d000,4,186a0,3e8,d116d000) at gettick+0xec

i8254_delay(3e8,0,4,fffffebf) at i8254_delay+0x11

ahd_reset(d116d000,0,804010,dab27eb0,d0202251) at ahd_reset+0xae

ahd_shutdown(d116d000,2e9b,dab27ee0,d05caedd) at ahd_shutdown+0x2e

dohooks(d0782000,1,dab27f00,d047a654) at dohooks+0x6b

boot(1008,0,dab27f40,0,d0781034) at boot+0x63

sys_reboot(d693dc20,dab27f68,dab27f58,ffffffff,30) at sys_reboot+0x26

syscall() at syscall+0x24e

--- syscall (number 55) ---

0x1c0009c1:

ddb> ps

   PID   PPID   PGRP    UID  S       FLAGS  WAIT          COMMAND

*21404      1  21404      0  7      0x4002                halt

    14      0      0      0  3    0x100200  bored         crypto

    13      0      0      0  3    0x100200  aiodoned      aiodoned

    12      0      0      0  2    0x100200                update

    11      0      0      0  3    0x100200  cleaner       cleaner

    10      0      0      0  3    0x100200  reaper        reaper

     9      0      0      0  3    0x100200  pgdaemon      pagedaemon

     8      0      0      0  2    0x100600                pfpurge

     7      0      0      0  3    0x100200  usbtsk        usbtask

     6      0      0      0  3    0x100200  usbevt        usb0

     5      0      0      0  3    0x100200  acpi_idle     acpi0

     4      0      0      0  3    0x100200  bored         syswq

     3      0      0      0  3    0x100200                idle0

     2      0      0      0  3    0x100200  kmalloc       kmthread

     1      0      1      0  3      0x4080  wait          init

     0     -1      0      0  2     0x80200                swapper

ddb> boot r

panic: mtx_enter: locking against myself

Stopped at      Debugger+0x4:   leave

RUN AT LEAST 'trace' AN...
[ message continues ]

More info: with bsd.mp, reboot drops to ddb too, but differently.

(GENERIC.MP dmesg is added right at the bottom). halt -p works.
At this point 'c' allows the reboot/halt to proceed, so at least

I no longer need a power-cycle.
This works ok in 4.0, not in 4.1/newer.
sycing disks... done

Stopped at      __mp_lock+0x3e: movl    0x4(%edx),%eax

ddb{1}> tr

__mp_lock(d07cc144,d048767a,dac34f1c,dac34f1c) at __mp_lock+0x3e

i386_softintlock(0,d0350058,d6b50010,10,dac30010) at i386_softintlock+0x10

Xintrltimer() at Xintrltimer+0x47

--- interrupt ---

cpu_idle_cycle(d1270800) at cpu_idle_cycle+0xf

Bad frame pointer: 0xd0911e78

ddb{1}> ps

   PID   PPID   PGRP    UID  S       FLAGS  WAIT          COMMAND

  6898      1   6898      0  7   0x2004002                reboot

    15      0      0      0  3    0x100200  bored         crypto

    14      0      0      0  3   0x2100200  aiodoned      aiodoned

    13      0      0      0  2   0x2100200                update

    12      0      0      0  3   0x2100200  cleaner       cleaner

    11      0      0      0  3    0x100200  reaper        reaper

    10      0      0      0  3   0x2100200  pgdaemon      pagedaemon

     9      0      0      0  2   0x2100600                pfpurge

     8      0      0      0  3   0x2100200  usbtsk        usbtask

     7      0      0      0  3   0x2100200  usbevt        usb0

     6      0      0      0  3   0x2100200  acpi_idle     acpi0

*    5      0      0      0  7    0x100200                idle1

     4      0      0      0  3    0x100200  bored         syswq

     3      0      0      0  3    0x100200                idle0

     2      0      0      0  3   0x2100200  kmalloc       kmthread

     1      0      1      0  3   0x2004080  wait          init

     0     -1      0      0  3   0x2080200  scheduler     swapper
Another time,
syncing disks... done

Stopped at      lapic_delay+0x3a:       cmpl    %esi,%edi

ddb{0}> tr

lapic_delay(3e8,0,4,fffffebf) at lapic_delay+0x3a

ahd_reset(d1278000,0,8040...
[ message continues ]

same box ... -current MP, looks like two ddb running at the same time.
# reboot

/etc/rc.shutdown in progress...

/etc/rc.shutdown complete.

sycing disks... done

pSatnoipcp:e dm taxt_enter: lockin g  a  g ai_n_mspt_ lmoycske+l0fx

ep:a nmiocv:l mtx_enter :  lo 0cxki4n(g% eadgxa)i,n%seta xm        3

sReUlNf                                                    y

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sOeUlTfP

Tp aWnHiEcN:  RmEtPxO_ReTnItNeGr :T HlIoSc kPiAnNgI Ca!g

       U

iDnOs tN OmTy sEeVlEfN                                  a

BpOaTnHiEcR:  RmEtPxO_ReTnItNeGr :T HlIoSc kWiInTgH OaUgTa iInNsCtL

UmDyIsNeGl fT

ApTa nIiNcF:O RmMtAxT_IeOnNt!e

panic: mtx_enter: locking against myself

panic: mtx_enter: locking against myself

panic: mtx_enter: locking against myself

panic: mtx_enter: locking against myselfpanic:

cpu1: fp_save ipi didn't (P)panic:

mtx_enter: locking against myself

panic: mtx_enter: locking against myself

panic: mtx_enter: locking against myself

panic: mtx_enter: locking against myself

panic: mtx_enter: locking against myself

panic: mtx_enter: locking against myself

[repeats]
I won't re-quote the last mail again, the other details are all

here: http://marc.info/?l=openbsd-misc&m=119739509606536&w=2