[SOLVED] Re: [patch] enhance powerd(8) to handle max temperature
Hajimu UMEMOTO
ume at freebsd.org
Tue Jul 31 14:43:20 UTC 2007
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!
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%
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.
Please refer the following document for detail:
http://www.acpi.info/DOWNLOADS/ACPIspec-2-0c.pdf
Sincerely,
--
Hajimu UMEMOTO @ Internet Mutual Aid Society Yokohama, Japan
ume at mahoroba.org ume@{,jp.}FreeBSD.org
http://www.imasy.org/~ume/
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