Date: Wed, 21 Dec 2005 14:26:18 +0100 From: Fredrik Lindberg <fli+freebsd-current@shapeshifter.se> To: Tobias Roth <roth@iam.unibe.ch> Cc: current@freebsd.org Subject: Re: IBM Thinkpad Fan Control (acpi_ibm) Message-ID: <43A957FA.8090005@shapeshifter.se> In-Reply-To: <20051221100954.GB24363@droopy.unibe.ch> References: <20051221100954.GB24363@droopy.unibe.ch>
next in thread | previous in thread | raw e-mail | index | archive | help
Tobias Roth wrote: > Hi > > With acpi_ibm.ko, I can monitor fan speed, thermal sensors and do > many other nice things. However, my Thinkpad (a T43p) has an awfully > noisy fan, that, once the notebook reaches its standard working > temperature (around 45 deg C), turns on and never stops again. > > The generally accepted solution his to manually lower the fan speed > and live with the higher temperatures, which will still be in an > acceptable range even with slow running fans. The discussion and a > utility for Windows can be found here [1], and a linux tool is > described here [2]. > > Now my question. Since acpi_ibm.ko can already read temperature > sensors and fan speed, would it be feasable to teach it to control > fan speed as well? Is anyone working on it already? Or can someone > outline the steps that have to be taken so I can take a look and > see if I can do it myself? > > thanks, t. I don't know if somebody is working on it, but it shouldn't be too hard to add it to acpi_ibm. Just parse the relevant bits from the linux patch and add a new sysctl method for fan speed in the acpi_ibm_sysctl_set() function in the file sys/dev/acpi_support/acpi_ibm.c I did this a while ago for but for fan enable/disable, but that is really useless because the only thing you can accomplish with the fan off is a fried laptop (although, it will be quiet :)). It's probably quite dangerous to mess with the fan speed too, because even if the fan is running at low speed you risk overheating your system. Fredrik Lindberg
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?43A957FA.8090005>