Panic on suspend

Hi,
I got a fully reproduceable panic while trying to suspend (to S3) on my laptop.
FreeBSD is -CURRENT from Monday.

I'm using a modified DSDT which used to work before I updated on Monday.
dmesg from after reboot is attacched.

Here comes gbd output


Fatal trap 12: page fault while in vm86 mode
fault virtual address	= 0x2000
fault code				= user write, page not present
instruction pointer		= 0xc000:0x5195
stack pointer			= 0x0:0xfe4
frame pointer			= 0x0:0x0
code segment			= base 0x600005, limit 0x2, type 0x11
						= DPL 1, pres 0, def32 0, gran 0
processor eflag			= interrupt enabled, resume, mv86, IOPL = 0
current process 		= 1046 (acpiconf)
[thread pid 1046 tid 100084]
Stopped at 0x5159: *** error reading from address 5159 ***

db> tr
Tracing pid 1046 tid 100084 td 0xc27645c0 
(null)(ff000e2c3,f000ff53,f000ff54,f00092da) at 0x5195
_end(ccce4fab,b638f354,3a6c5da3,ec956de5,fe6dff6c) at 0xf000ff53

db> where
Tracing pid 1046 tid 100084 td 0xc27645c0 
kdb_enter(c08d00f2,c08e69ce,c08cbfd1,c08ee7f9,2b8) at kdb_enter+0x31
witness_checkorder(c2cc2a54,9,c08ee7f9,2b8,0) at witness_checkorder+0xc9
_mtx_lock_flags(c2cc2a54,0,c08ee7f9,2b8,0) at _mtx_lock_flags+0x85
trap_pfault(c0c21fa8,0,2000,c0c21fa8,2000) at trap_pfault+0xa1
trap (0,0,0,1000,0) at trap+0x34b
calltrap() at calltrap+0x5
---trap 0xc, eip = 0x5195, esp = 0xc0c21fe8, ebp = 0 ---

db> next
panic: blockable sleep lock (sleep mutex) process lock _at_
/usr/src/sys/i386/i386/trap.c:696
KDB: enter: panic
After 2 instructions (0 loads, 0 stores),
[thread 1046 tid 1000084]
stopped at kdb_enter+0x31: ret

Thanks for your help
Filippo