usb lpt crashes FreeBSD

Hi,

I regularly get crashes when printing to my laserprinter, connected to a 
usb port. This is on FreeBSD 5.3-STABLE from 18-01-2005.

Sometimes, not every time, my computer will hang after having sent the 
print job, i.e. the job will be printed, but in ulptclose() the computer 
hangs (see bottom of message for stacktrace).

I saw a commit a few weeks back about this problem, which seemed to 
improve the situation somewhat, but it still crashes *very* regularly :(

Any fixes for this?

Cheers,
Marc.

 > ulpt0: Samsung Electronics Co., Ltd. Samsung ML-1510_700, rev 
1.10/1.00, addr
+3, iclass 7/1
 > ulpt0: using bi-directional mode
 >
 > Fatal trap 12: page fault while in kernel mode
 > fault virtual address = 0x4c
 > fault code            = supervisor read, page not present
 > instruction pointer   = 0x8:0xc04e6be9
 > stack pointer         = 0x10:0xefe71b04
 > frame pointer         = 0x10:0xefe71b20
 > 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               = 68367 (lpd)
 > trap number           = 12
 > panic: page fault
 > KDB: stack backtrace:
 > kdb_backtrace(100,c3bb6c80,10,efe71ac4,c) at kdb_backtrace+0x29
 > panic(c06d3bfd,c07003ba,0,fffff,c33be79b) at panic+0xa8
 > trap_fatal(efe71ac4,4c,c3bb6c80,c275ca8c,c) at trap_fatal+0x27c
 > trap_pfault(efe71ac4,0,4c) at trap_pfault+0x1cf
 > trap(18,10,10,0,c684e300) at trap+0x2ed
 > calltrap() at calltrap+0x5
 > --- trap 0xc, eip = 0xc04e6be9, esp = 0xefe71b04, ebp = 0xefe71b20 ---
 > usb_transfer_complete(c2e22c00) at usb_transfer_complete+0xcd
 > uhci_abort_xfer(c2e22c00,6,efe71b5c,c04e6b03,c2e22c00) at 
uhci_abort_xfer+0xcf
 > uhci_device_bulk_abort(c2e22c00) at uhci_device_bulk_abort+0xd
 > usbd_ar_pipe(c684e300) at usbd_ar_pipe+0x1f
 > usbd_abort_pipe(c684e300,c5574a50,efe71ba4,c0500048,c074b258) at
+usbd_abort_pipe+0xb
 > ulptclose(c074b258,2,2000,c3bb6c80,c071a400) at ulptclose+0x92
 > spec_close(efe71bbc,efe71be4,c05958a4,efe71bbc,c07403a0) at 
spec_close+0x310
 > spec_vnoperate(efe71bbc) at spec_vnoperate+0x13
 > vn_close(c5574a50,2,c6850300,c3bb6c80,efe71c14) at vn_close+0x40
 > vn_closefile(c2e47cc0,c3bb6c80) at vn_closefile+0xc2
 > fdrop_locked(c2e47cc0,c3bb6c80,0,efe71ccc,c05189e7) at fdrop_locked+0xa4
 > fdrop(c2e47cc0,c3bb6c80,c0740960,c6676948,0) at fdrop+0x41
 > closef(c2e47cc0,c3bb6c80,0,c33be710,0) at closef+0x237
 > close(c3bb6c80,efe71d14,1,0,292) at close+0x169
 > syscall(2f,2f,2f,805a67f,805f080) at syscall+0x27b