4.9-PRERELEASE wedges on reboot

[dglo at ssec.wisc.edu]

Peter Jeremy wrote:
> I've just updated to a recent -STABLE (~12 hours old) and my Compaq
> 1592 laptop now wedges on a reboot - though it will boot normally
> on power-on.  I can't provide a traceback because Ctrl-Alt-Esc
> doesn't work.
> 
> Following is a dmesg from a successful verbose boot with a marker
> (####) showing where it hangs on reboot (immediately after reporting
> the PCI config for pcic0).  sio1 and ep0 are PCMCIA cards.
> 
> Any ideas?

My machine hung after I updated it on Thursday.  I managed to track it
down to a commit which touched 4 files:

  cam/scsi/scsi_cd.c     1.31.2.15
  cam/scsi/scsi_da.c     1.42.2.45
  kern/subr_taskqueue.c  1.1.2.3
  sys/taskqueue.h        1.3.2.2

Removing those revisions got me a working system.