On Wed, 30 Dec 2009 12:36:28 -0700 joshua stein <j...@openbsd.org> wrote:
> > i experience on my Thinkpad X200, that sometimes the fan gets stuck > > at fullspeed. (This time it is after 19h of uptime.) > > The notebook is idle, temperatures are fine, but the fan just goes > > to fullspeed and stays there. > > Normaly the regulation works fine in tandem with apmd -C. > > Rebooting will reset the fan to normal behaviour. > > nothing controls fan speeds in the kernel. the thinkpad embedded > controller defaults to "auto" mode, which is supposed to regulate > fan speeds itself and speed up or slow down depending on cpu and hdd > temperatures. you can usually hear it speed up while doing > cpu-intensive tasks, but unfortunately it will never slow down > enough that you can't hear it. > > you can try checking if there are any EC/BIOS updates for your > laptop on lenovo's website. > > otherwise, you can force the fan down in the kernel. just last > night i wrote this to quiet down my idle thinkpad x301 by turning > the fan down when the temperatures are low: > http://jcs.org/patches/openbsd-acpithinkpad_fan_control.diff > > but use it at your own risk and don't expect it to be committed. it > could probably use some sysctl knobs to define the max temperatures, > but the hard-coded ones are working ok for me right now. Thanks Joshua! I wrongly was under the impression that some poking of acpi registers was already involved. So i checked for a news bios and found the latest might actually address the issue: (New) Improved the speed control of cooling fan. Thanks again, - Robert
