uhci panic

[Patrick Welche <prlw1%cam.ac.uk@localhost>]

I was just changing virtual consoles (ctl-alt-f1) on a this morning's
-current/amd64 (intel pineview drmkms), when:

(gdb) bt
#0  0xffffffff804b8a65 in cpu_reboot (howto=howto@entry=260, 
    bootstr=bootstr@entry=0x0) at ../../../../arch/amd64/amd64/machdep.c:671
#1  0xffffffff8068c132 in vpanic (fmt=fmt@entry=0xffffffff8099b9ba "trap", 
    ap=ap@entry=0xfffffe80439c2d40) at ../../../../kern/subr_prf.c:340
#2  0xffffffff8068c1ed in panic (fmt=fmt@entry=0xffffffff8099b9ba "trap")
    at ../../../../kern/subr_prf.c:256
#3  0xffffffff806ced5f in trap (frame=0xfffffe80439c2e60)
    at ../../../../arch/amd64/amd64/trap.c:298
#4  0xffffffff80100f46 in alltraps ()
#5  0xffffffff8071027a in uhci_reset (sc=<optimized out>)
    at ../../../../dev/usb/uhci.c:1766
Backtrace stopped: previous frame inner to this frame (corrupt stack?)

Can I trust this backtrace, e.g.:
(gdb) thread apply all bt

Thread 1 (<kvm>):
#0  0xffffffff804b8a65 in ?? ()
#1  0x0000000000000104 in ?? ()
#2  0xffffffff8099b9ba in ?? ()
#3  0xfffffe80439c2d30 in ?? ()
#4  0xffffffff8068c132 in ?? ()
#5  0xfffffe807f2d7860 in ?? ()
#6  0xfffffe80439c2e60 in ?? ()
#7  0x0000000000000006 in ?? ()
#8  0xfffffe80439c2d88 in ?? ()
#9  0xffffffff8068c1ed in ?? ()
#10 0xfffffe8000000008 in ?? ()
#11 0xfffffe80439c2d98 in ?? ()
#12 0xfffffe80439c2d58 in ?? ()
#13 0xfffffe807f2d7860 in ?? ()
#14 0xfffffe80439c2e60 in ?? ()
#15 0x0000000000000000 in ?? ()


The other thing is that *nothing* is connected to that computer's
USB sockets - both keyboard and mouse are PS2. (dmesg | grep -i usb
tells me nothing is connected internally either.)


Cheers,

Patrick