bin/138060: powerd hangs the system solid

[Mikhail T.]

>Number:         138060
>Category:       bin
>Synopsis:       powerd hangs the system solid
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sat Aug 22 05:00:13 UTC 2009
>Closed-Date:
>Last-Modified:
>Originator:     Mikhail T.
>Release:        FreeBSD 7.2-STABLE amd64
>Organization:
Virtual Estates, Inc. http://sybpipe.com/
>Environment:
System: FreeBSD aldan.algebra.com 7.2-STABLE FreeBSD 7.2-STABLE #0: Thu Jul 9 18:42:04 EDT 2009 mi at aldan.algebra.com:/meow/obj/var/src/sys/SILVER-SMP amd64

	Two dual-core Opterons-275

dev.cpu.0.freq_levels: 2205/-1 1929/-1 1653/-1 1378/-1 1102/-1 826/-1 551/-1 275/-1

>Description:
	powerd starts up fine and proceeds to lower the CPU-frequency
	from the full 2205MHz to 275MHz. Shortly after that the system
	locks up solid. Maybe, this is due to another attempt at halving
	(below the minimum speed listed in freq_levels).

>How-To-Repeat:

	powerd

>Fix:

	The proper fix would require figuring out, what exactly is
	wrong. A work-around would simply add the minimum allowed
	speed to the command-line options for powerd, so that the
	administrator could set that up.

	This would be handy even on a non-hanging system, where the
	admin may want to disallow it to go below certain speed for
	performance reasons.
>Release-Note:
>Audit-Trail:
>Unformatted: