linux-kernel - Re: Athlon L110 CPU and powernow-k8

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Message-ID: <1271702534.6445.9.camel@tomoyo>
Date:	Mon, 19 Apr 2010 20:42:14 +0200
From:	Josselin Mouette <joss@...ian.org>
To:	"Langsdorf, Mark" <mark.langsdorf@....com>
Cc:	"'linux-kernel@...r.kernel.org'" <linux-kernel@...r.kernel.org>
Subject: Re: Athlon L110 CPU and powernow-k8

Le lundi 19 avril 2010 à 06:43 -0700, Langsdorf, Mark a écrit : 
> > I wonder what is possible to do to support this CPU correctly in the
> > kernel. The only sane solution I can think of is to hardcode the
> > P-states for this CPU model in the powernow-k8 driver itself. 
> 
> I think that hard-coding P-states into the PowerNow 
> driver is not a mantainable solution.

I agree this is not optimal, but I think there are similar bits in other
drivers. 

> I don't quite understand why the you think that
> a custom DSDT as a BIOS hack, but think that
> adding custom frequencies to the driver itself is
> acceptable.

The first solution implies building a custom kernel before being able to
use the system. The second solution does not. I’m looking for a solution
that works out of the box, and does not require to be able to compile
ASL code nor a kernel.

> The last time this issue came up on cpufreq, Dave
> Jones nixed a general solution to add custom P-states
> through the driver on the grounds that people would
> undervolt their systems, causing a lot of screwy,
> unpredictable behavior.  I agreed with his opinion
> then and I don't see anything in this mesage to
> change that view.

If you want to screw your system, this is already feasible by hacking
the DSDT table itself. Granted, this is not the kind of stuff the
average n00b would do.

Given how Acer doesn’t give a shit about OSes other than XP - not even
other Windows versions - I don’t think they are likely to provide a
fixed BIOS. If they can be convinced, I don’t know how. And if they
can’t - what are we left with?

Cheers,
-- 
 .''`.      Josselin Mouette
: :' :
`. `'  “If you behave this way because you are blackmailed by someone,
  `-    […] I will see what I can do for you.”  -- Jörg Schilling

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