jhb ff87bab779 Fix a few minor issues based on a bug report and reading over the HPET
spec:
- Use read/modify/write cycles to enable and disable the HPET instead of
  writing 0 to reserved bits.
- Shutdown the HPET during suspend as encouraged by the spec.
- Fail to attach to an HPET with a period of zero.

MFC after:	1 week
PR:		kern/119675 [3]
Reported by:	Leo Bicknell | bicknell ufp.org
2008-01-15 18:50:47 +00:00
..
2007-11-08 21:20:34 +00:00
2005-09-11 18:39:03 +00:00
2005-09-11 18:39:03 +00:00
2006-04-21 19:06:29 +00:00
2006-02-21 03:16:58 +00:00