snd_pcm related panic

hi,
i can reproduce the following panic on my system with loading snd_pcm
and snd_es137x, using it for a while (xmms), unloading the modules and
then reloading snd_pcm again.

panic: from debugger
panic messages:
--
Fatal trap 12: page fault while in kernel mode
fault virtual address   = 0x7c
fault code              = supervisor read, page not present
instruction pointer     = 0x8:0xc6b627bf
stack pointer           = 0x10:0xd86fea44
frame pointer           = 0x10:0xd86fea5c
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, def32 1, gran 1
processor eflags        = interrupt enabled, resume, IOPL = 0
current process         = 9529 (kldload)
panic: from debugger


Fatal trap 3: breakpoint instruction fault while in kernel mode
instruction pointer     = 0x8:0xc06520f4
stack pointer           = 0x10:0xd86fe7dc
frame pointer           = 0x10:0xd86fe7e8
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, def32 1, gran 1
processor eflags        = IOPL = 0
current process         = 9529 (kldload)
panic: from debugger
Uptime: 1d15h23m49s
Dumping 511 MB
16 32 48 64 80 96 112 128 144 160 176 192 208 224 240 256 272 288 304
320 336 352 368 384 400 416 432 448 464 480 496
--
Reading symbols from
/usr/obj/usr/src-current/sys/DEBUG/modules/usr/src-current/sys/modules/linux/linux.ko.debug...done.
Loaded symbols for
/usr/obj/usr/src-current/sys/DEBUG/modules/usr/src-current/sys/modules/linux/linux.ko.debug
Reading symbols from /boot/kernel/ng_UI.ko...done.
Loaded symbols for /boot/kernel/ng_UI.ko
Reading symbols from /boot/kernel/netgraph.ko...done.
Loaded symbols for /boot/kernel/netgraph.ko
Reading symbols from /boot/kernel/ng_ether.ko...done.
Loaded symbols for /boot/kernel/ng_ether.ko
Reading symbols from /boot/kernel/ng_pppoe.ko...done.
Loaded symbols for /boot/kernel/ng_pppoe.ko
Reading symbols from /boot/kernel/ng_socket.ko...done.
Loaded symbols for /boot/kernel/ng_socket.ko
Reading symbols from /boot/kernel/pf.ko...done.
Loaded symbols for /boot/kernel/pf.ko
Reading symbols from /boot/kernel/pfsync.ko...done.
Loaded symbols for /boot/kernel/pfsync.ko
Reading symbols from /boot/kernel/pflog.ko...done.
Loaded symbols for /boot/kernel/pflog.ko
Reading symbols from
/usr/obj/usr/src-current/sys/DEBUG/modules/usr/src-current/sys/modules/aio/aio.ko.debug...done.
Loaded symbols for
/usr/obj/usr/src-current/sys/DEBUG/modules/usr/src-current/sys/modules/aio/aio.ko.debug
Reading symbols from /boot/kernel/acpi.ko...done.
Loaded symbols for /boot/kernel/acpi.ko
Reading symbols from
/usr/obj/usr/src-current/sys/DEBUG/modules/usr/src-current/sys/modules/vinum/vinum.ko.debug...done.
Loaded symbols for
/usr/obj/usr/src-current/sys/DEBUG/modules/usr/src-current/sys/modules/vinum/vinum.ko.debug
Reading symbols from
/usr/obj/usr/src-current/sys/DEBUG/modules/usr/src-current/sys/modules/linprocfs/linprocfs.ko.debug...done.
Loaded symbols for
/usr/obj/usr/src-current/sys/DEBUG/modules/usr/src-current/sys/modules/linprocfs/linprocfs.ko.debug
Reading symbols from
/usr/obj/usr/src-current/sys/DEBUG/modules/usr/src-current/sys/modules/if_tap/if_tap.ko.debug...done.
Loaded symbols for
/usr/obj/usr/src-current/sys/DEBUG/modules/usr/src-current/sys/modules/if_tap/if_tap.ko.debug
Reading symbols from /boot/kernel/ng_bridge.ko...done.
Loaded symbols for /boot/kernel/ng_bridge.ko
Reading symbols from /boot/kernel/vmnet.ko...done.
Loaded symbols for /boot/kernel/vmnet.ko
Reading symbols from /boot/kernel/snd_es137x.ko...done.
Loaded symbols for /boot/kernel/snd_es137x.ko
Reading symbols from /boot/kernel/snd_pcm.ko...done.
Loaded symbols for /boot/kernel/snd_pcm.ko
#0  doadump () at /usr/src-current/sys/kern/kern_shutdown.c:240
240             dumping++;
(kgdb) 
(kgdb) bt
#0  doadump () at /usr/src-current/sys/kern/kern_shutdown.c:240
#1  0xc04ff219 in boot (howto=260)
    at /usr/src-current/sys/kern/kern_shutdown.c:372
#2  0xc04ff5f8 in panic () at
/usr/src-current/sys/kern/kern_shutdown.c:550
#3  0xc043c7d2 in db_panic () at
/usr/src-current/sys/ddb/db_command.c:450
#4  0xc043c732 in db_command (last_cmdp=0xc06e8560, cmd_table=0x0, 
    aux_cmd_tablep=0xc06ab1a8, aux_cmd_tablep_end=0xc06ab1ac)
    at /usr/src-current/sys/ddb/db_command.c:346
#5  0xc043c875 in db_command_loop ()
    at /usr/src-current/sys/ddb/db_command.c:472
#6  0xc043f895 in db_trap (type=12, code=0)
    at /usr/src-current/sys/ddb/db_trap.c:73
#7  0xc0651e3c in kdb_trap (type=12, code=0, regs=0xd86fea04)
    at /usr/src-current/sys/i386/i386/db_interface.c:171
#8  0xc0662d16 in trap_fatal (frame=0xd86fea04, eva=0)
    at /usr/src-current/sys/i386/i386/trap.c:816
#9  0xc06629e2 in trap_pfault (frame=0xd86fea04, usermode=0, eva=124)
    at /usr/src-current/sys/i386/i386/trap.c:735
#10 0xc066253d in trap (frame=
      {tf_fs = 24, tf_es = 16, tf_ds = 16, tf_edi = 0, tf_esi = 0,
tf_ebp = -663754148, tf_isp = -663754192, tf_ebx = -1047110064, tf_edx =
4, tf_ecx = 0, tf_eax = 0, tf_trapno = 12, tf_err = 0, tf_eip =
-961140801, tf_cs = 8, tf_eflags = 66182, tf_esp = 16, tf_ss = 0}) at
/usr/src-current/sys/i386/i386/trap.c:420
#11 0xc0653838 in calltrap () at {standard input}:94
#12 0xc6b5ddb1 in dsp_register () from /boot/kernel/snd_pcm.ko
#13 0xc6b61f05 in pcm_chn_add () from /boot/kernel/snd_pcm.ko
#14 0xc6b62096 in pcm_addchan () from /boot/kernel/snd_pcm.ko
#15 0xc68abaf9 in es_pci_attach () from /boot/kernel/snd_es137x.ko
#16 0xc0519ff9 in device_probe_and_attach (dev=0xc440cb00) at
device_if.h:39
#17 0xc051ad8e in bus_generic_driver_added (dev=0x0, driver=0xc68ad380)
    at /usr/src-current/sys/kern/subr_bus.c:1930
#18 0xc0518bd0 in devclass_add_driver (dc=0xc43930c0, driver=0xc68ad380)
    at bus_if.h:71
#19 0xc051bfdf in driver_module_handler (mod=0xc4cd7d00,
what=-963980416, 
    arg=0xc68ad398) at /usr/src-current/sys/kern/subr_bus.c:2369
#20 0xc04f3e91 in module_register_init (arg=0xc68ad3ac)
    at /usr/src-current/sys/kern/kern_module.c:108
#21 0xc04edd50 in linker_file_sysinit (lf=0x0)
    at /usr/src-current/sys/kern/kern_linker.c:192
#22 0xc04ee0d7 in linker_load_file (
    filename=0xc194c360 "/boot/kernel/snd_es137x.ko", result=0xd86feca8)
    at /usr/src-current/sys/kern/kern_linker.c:357
#23 0xc04f0d17 in linker_load_module (kldname=0xc06ce8e0 "<?iÀ\200èlÀÈ",
    modname=0xc194c360 "/boot/kernel/snd_es137x.ko", parent=0x0,
verinfo=0x0, 
    lfpp=0xd86fecd4) at /usr/src-current/sys/kern/kern_linker.c:1670
#24 0xc04eeef3 in kldload (td=0xc4564d20, uap=0x0)
    at /usr/src-current/sys/kern/kern_linker.c:773
#25 0xc06630d0 in syscall (frame=
      {tf_fs = 47, tf_es = 47, tf_ds = 47, tf_edi = 0, tf_esi =
-1077941044, tf_ebp = -1077941088, tf_isp = -663753356, tf_ebx = 0,
tf_edx = -1077941048, tf_ecx = 2, tf_eax = 304, tf_trapno = 12, tf_err =
2, tf_eip = 671866943, tf_cs = 31, tf_eflags = 531, tf_esp =
-1077941140, tf_ss = 47})
    at /usr/src-current/sys/i386/i386/trap.c:1010
#26 0xc065388d in Xint0x80_syscall () at {standard input}:136
---Can't read userspace from dump, or kernel process---

(kgdb) 


regards,
seb

$ uname -a
FreeBSD tyrael.linnet 5.2-CURRENT FreeBSD 5.2-CURRENT #5: Sat Jan 31
23:07:17 CET 2004    
seb_at_tyrael.linnet:/usr/obj/usr/src-current/sys/DEBUG  i386