Annoyances with passive thermal code (acpi_thermal)

[Hajimu UMEMOTO]

Hi,

>>>>> On Sat, 13 Aug 2005 19:38:42 -0700
>>>>> "Kevin Oberman" <oberman at es.net> said:

oberman> I've noted an unpleasant mis-behavior in acpi_thermal.

oberman> 1. Killed powerd
oberman> 2. Set dev.cpu.0.freq to 1200 (I was on batteries and wanted to stretch
oberman>    them) 
oberman> 3. Started a BIG build...openoffice

oberman> The temp went up over _PSV and the CPU was slowed to 1050. The CPU
oberman> cooled for a while and the freq was reset to 1800 which started draining
oberman> my battery way too fast.

It's curious that even when CPU speed is slowed, the temperature go up
over _PSV.

oberman> Ideally, acpi_thermal should store the frequency when it cuts speed and
oberman> restore that speed when the CPU cools, not the maximum speed.

CPUFREQ_SET() does it, actually.  However, since CPU speed is restored
by degrees, we couldn't use the facility effectively.  Please try the
attached patch.

Sincerely,

-------------- next part --------------
A non-text attachment was scrubbed...
Name: acpi_thermal.c-saved_level.diff
Type: text/x-patch
Size: 2780 bytes
Desc: not available
Url : http://lists.freebsd.org/pipermail/freebsd-acpi/attachments/20050815/c0aecfbc/acpi_thermal.c-saved_level.bin
-------------- next part --------------
--
Hajimu UMEMOTO @ Internet Mutual Aid Society Yokohama, Japan
ume at mahoroba.org  ume@{,jp.}FreeBSD.org
http://www.imasy.org/~ume/