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Message-ID: <1361287675.2323.26.camel@rzhang1-mobl4>
Subject: Re: thermal governor: does it actually work??
From: Zhang Rui <rui.zhang@intel.com>
To: Borislav Petkov <bp@alien8.de>
Cc: Peter Feuerer <peter@piie.net>, Alexander Lam <azl@andrew.cmu.edu>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Andreas Mohr <andi@lisas.de>
Date: Tue, 19 Feb 2013 23:27:55 +0800
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On Tue, 2013-02-19 at 16:05 +0100, Borislav Petkov wrote:
> On Tue, Feb 19, 2013 at 10:51:04PM +0800, Zhang Rui wrote:
> > Okay, here I see the problem, say you want to turn on the fan at 60C and
> > turn it off at 55C, is this what you want?
> > hmmm, is it possible to do some tricks in acerhdf driver?
> > say,
> > only one active trip point as before. but change acerhdf_get_trip_temp
> > to:
> > acerhdf_get_trip_temp()
> > {
> > 	if (fan is on)
> > 		return 55;
> > 	else
> > 		return 60;
> > }
> > 
> > In this way, when the fan is off and the temperature is raising, the fan
> > will be turned on at 60C because we have an active trip point of 60C.
> > And when the fan is turned on and the temperature starts to drop, the
> > fan will be turned off at 55C.
> 
> Makes a sense to me. I was questioning the need for 4 trip points too.

I do not understand why you need 4 trip points for the issue above,
unless I missed another gap here.

> We probably would need a second, critical trip point though, just in
> case.
> 
yeah, it is okay to have a critical trip point.

thanks,
rui