[SOLVED] Re: [patch] enhance powerd(8) to handle max temperature

Pietro Cerutti gahr at gahr.ch
Tue Jul 31 14:55:03 UTC 2007


Hajimu UMEMOTO wrote:
> Hi,
> 
>>>>>> On Tue, 31 Jul 2007 12:44:06 +0200
>>>>>> Pietro Cerutti <gahr at gahr.ch> said:
> 
> gahr> Nevermind, I finally got my passive cooling working.
> 
> Congratulation!

Thanx ;-)

> 
> gahr> I don't know if the values of _TC1, _TC2 and TSP are meaningful, but it
> gahr> seems to work for me, having a _PSV value of 65C.
> gahr> Any suggestions on those values are welcome.
> 
> The cpufreq is controlled according to the following formula:
> 
> 	P [%] = _TC1 * ( Tn - Tn-1 ) + _TC2 * ( Tn - _PSV )
> 	Pn = Pn-1 + HW[ - P ] where 0% <= Pn <= 100%

Been there, done that ;-) I saw this formula on the ACPI specs, but I
feel like I don't have the knowledge to tailor _TC1 and _TC2 to my

> 
> And, this evaluation is examined every _TSP / 10 second.
> I'm not sure which values are appropriate for your box, but my laptop
> has the following values:
> 
> 	Name (_TC1, Zero)
> 	Name (_TC2, 0x0C)
> 	Name (_TSP, 0x28)
> 
> The values are same as you chose.

;-) I took the first two values I found in an ACPI asl on the net.

> Please refer the following document for detail:
> 
> 	http://www.acpi.info/DOWNLOADS/ACPIspec-2-0c.pdf

Maybe during vacation :-)

> 
> Sincerely,

Thanks for your help!

> 
> --
> Hajimu UMEMOTO @ Internet Mutual Aid Society Yokohama, Japan
> ume at mahoroba.org  ume@{,jp.}FreeBSD.org
> http://www.imasy.org/~ume/


-- 
Pietro Cerutti

PGP Public Key:
http://gahr.ch/pgp

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