Subject: Re: Laptops & CPU frequency
From: Robert Love <rml@ximian.com>
To: Matthew Garrett <mgarrett@chiark.greenend.org.uk>
Cc: linux-kernel@vger.kernel.org
In-Reply-To: <E1Afj2b-0004QN-00@chiark.greenend.org.uk>
References: <20040111025623.GA19890@ncsu.edu>
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	 <E1Afj2b-0004QN-00@chiark.greenend.org.uk>
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Date: Sun, 11 Jan 2004 12:13:20 -0500
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On Sun, 2004-01-11 at 12:06, Matthew Garrett wrote:

> Is this true even when the speed changes aren't done through Speedstep?
> Some older (PII/non-Speedstep PIIIs) Thinkpads automatically change
> speed based on presence of AC power, but do it in a way that's exposed
> as an ACPI throttling state rather than a performance state. My
> experience is that this doesn't result in cpuinfo getting updated, and
> various kernel things seem to become unhappy. On the other hand, I
> haven't tried this since 2.5.5something - I just told the BIOS not to
> touch stuff instead.

No - if the laptop changes speed on its own, using a system that Linux
does not understand, then Linux won't know about the change,
/proc/cpuinfo will not be updated, and stuff won't go too good.

	Robert Love


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