kern/108581: [sysctl] sysctl: hw.acpi.cpu.cx_lowest: Invalid argument

[Bruce Cran]

On Fri, 20 Mar 2009 00:30:03 GMT
Daniel Dvořák <dandee at hellteam.net> wrote:

> The following reply was made to PR kern/108581; it has been noted by
> GNATS.
> 
> From: =?UTF-8?Q?Daniel_Dvo=C5=99=C3=A1k?= <dandee at hellteam.net>
> To: <bug-followup at FreeBSD.org>,
> 	<lars.stokholm at gmail.com>
> Cc:  
> Subject: Re: kern/108581: [sysctl] sysctl: hw.acpi.cpu.cx_lowest:
> Invalid argument Date: Fri, 20 Mar 2009 01:01:51 +0100
> 
>  This is a multi-part message in MIME format.
>  
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>  
>  Hi acpi team,
>  =20
>  today I have installed fbsd 7.1R on one box with this relativly old =
>  error and I was surprised about results .. it is the same:
>  =20
>  # uname -a
>  FreeBSD X.Y.Z 7.1-RELEASE FreeBSD 7.1-RELEASE #0: Thu Jan  1
> 14:37:25 = UTC 2009
> root at logan.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC  = i386
>  
>  # sysctl dev.cpu.0.cx_supported
>  dev.cpu.0.cx_supported: C1/0
>  
>  # sysctl hw.acpi.cpu.cx_lowest=3DC1
>  hw.acpi.cpu.cx_lowest: C1
>  sysctl: hw.acpi.cpu.cx_lowest: Invalid argument

I get the same error on my relatively ancient Athlon XP machine - I
originally bought it in 2002.  Since
it pre-dates all the CPU power-saving technologies I wouldn't expect
setting Cx to do anything, but it seems FreeBSD creates the sysctl
nodes regardless, and tries to initialize cx_lowest to C1 during boot.

-- 
Bruce Cran