cvs commit: src/sys/dev/acpi_support acpi_ibm.c

Markus Brueffer markus at
Sat Jan 14 18:02:40 PST 2006

Nate Lawson schrieb:
> Markus Brueffer wrote:
>> Nate Lawson schrieb:
>>> Markus Brueffer wrote:
>>>> markus      2006-01-14 00:39:10 UTC
>>>>  FreeBSD src repository (ports committer)
>>>>  Modified files:
>>>>    sys/dev/acpi_support acpi_ibm.c   Log:
>>>>  - Add support for setting the fan control mode to manual or automatic
>>>>  - Add support for adjusting the fan speed if the fan control mode is
>>>> manual
>>>>    Documentation for the relevant embedded controller register was
>>>> obtained from
>>>>    Tested on:      R51  by Fabian Keil
>>>>                  T41p by markus
>>>>  Requested by:   many
>>>>  Approved by:    philip
>>>>  MFC after:      1 week
>>>>    Revision  Changes    Path
>>>>  1.10      +55 -3     src/sys/dev/acpi_support/acpi_ibm.c
>>> Thanks for adding support for this but it should be noted that this can
>>> be very dangerous.  If your userland app tries to control the fanspeed
>>> and dies, your system could overheat.  Hopefully, the BIOS will override
>>> the user settings if the temp gets too high but that is a longshot when
>>> mucking with things at this low level.
>> That's why I didn't add support for it in the first place. The problem
>> is that especially with the T43 series there seems to be a fan problem.
>> If it reaches a certain threshold the fan is switched on, but never
>> switched off regardless how cool the notebook gets.
> That's probably a bug in acpi_thermal.  It needs a thorough debugging
> anyway.

If that's really the case and we can fix it there, all the better, but
Linux and Windows users have the same problems on T43's, so the problem
might be somewhere else.


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