ural(4) and panic on sleeping thread (6.1-R)

["José M. Fandiño"]

John Baldwin wrote:
> In kgdb, do 'proc 783', and then 'where' to get a stack trace of the thread 
> that did the wrong thing.   (The thread that panics is just an innocent 
> victim that bumped into the miscreant.)

(kgdb) proc 783
(kgdb) where
#0  0xc065f2c7 in sched_switch (td=0xc283e900, newtd=0xc2535780, flags=1)
     at /usr/src/sys/kern/sched_4bsd.c:973
#1  0xc06544e2 in mi_switch (flags=1, newtd=0x0)
     at /usr/src/sys/kern/kern_synch.c:336
#2  0xc066c012 in sleepq_switch (wchan=0x0)
     at /usr/src/sys/kern/subr_sleepqueue.c:445
#3  0xc066c102 in sleepq_wait (wchan=0xc2cfda00)
     at /usr/src/sys/kern/subr_sleepqueue.c:525
#4  0xc065422d in msleep (ident=0xc2cfda00, mtx=0x0, priority=76,
     wmesg=0xc08a076d "usbsyn", timo=0) at /usr/src/sys/kern/kern_synch.c:209
#5  0xc05ee105 in usbd_transfer (xfer=0xc2cfda00)
     at /usr/src/sys/dev/usb/usbdi.c:344
#6  0xc05ee125 in usbd_sync_transfer (xfer=0x0)
     at /usr/src/sys/dev/usb/usbdi.c:355
#7  0xc05ee901 in usbd_do_request_flags_pipe (dev=0xc276cc00, pipe=0x0,
     req=0xd4bf2a4c, data=0xd4bf2a4a, flags=0, actlen=0x0, timeout=5000)
     at /usr/src/sys/dev/usb/usbdi.c:982
#8  0xc05ee8a0 in usbd_do_request_flags (dev=0x0, req=0xd4bf2a4c,
     data=0xd4bf2a4a, flags=0, actlen=0x0, timo=5000)
     at /usr/src/sys/dev/usb/usbdi.c:953
#9  0xc05ee87e in usbd_do_request (dev=0xc276cc00, req=0xd4bf2a4c,
     data=0xd4bf2a4a) at /usr/src/sys/dev/usb/usbdi.c:945
#10 0xc05d7876 in ural_read (sc=0xc2768000, reg=0)
     at /usr/src/sys/dev/usb/if_ural.c:1545
#11 0xc05d7a43 in ural_bbp_write (sc=0xc2768000, reg=22 '\026', val=8 '\b')
     at /usr/src/sys/dev/usb/if_ural.c:1619
#12 0xc05d83d5 in ural_bbp_init (sc=0xc2768000)
     at /usr/src/sys/dev/usb/if_ural.c:1998
#13 0xc05d85bd in ural_init (priv=0xc2768000)
     at /usr/src/sys/dev/usb/if_ural.c:2104
#14 0xc05d76ae in ural_ioctl (ifp=0xc2796400, cmd=2149607696,
     data=0xd4bf2b08 "@1\222À|-\222À0+¿Ô")
     at /usr/src/sys/dev/usb/if_ural.c:1470
#15 0xc06b9c54 in if_setflag (ifp=0xc2796400, flag=0, pflag=0,
     refcount=0xc2796444, onswitch=0) at /usr/src/sys/net/if.c:1664