kern/77805: Boot hangs with ACPI enabled

[Nate Lawson]

Ron Johnson wrote:
> Any help would be appreciated! dmesg output and ASL are in the bug
> report.
> 
> http://www.freebsd.org/cgi/query-pr.cgi?pr=77805
> 
> With ACPI enabled, boot fails at "hw.acpi.cpu.cx_lowest: C1 -> C3". This
> statement is not in sysctl.conf or loader.conf and appears to be changed
> automatically. No issue in all previous 5.X versions. 5.3-STABLE
> downloaded from CVS on 2/19/2005 around 3pm EST.

You want to change the performance/economy settings in rc.conf.  Man 5 
rc.conf

The defaults were changed between 5.2.1 and 5.3:

src/etc/defaults/rc.conf:revision 1.206
date: 2004/05/29 04:52:37;  author: njl;  state: Exp;  lines: +1 -1
Throw the switch and enable use of the lowest idle states while online in
addition to offline.  This can be overridden in /etc/rc.conf if it causes
trouble although this has been stable since 2003/12.

I have no idea why C3 is unstable on your machine.  Please try 
overriding this with something like this and see if it helps:

performance_cx_state=HIGH
economy_cx_state=HIGH

-- 
Nate