IBM Thinkpad Fan Control (acpi_ibm)

[Markus Brueffer]

Tobias Roth schrieb:
> On Sat, Jan 14, 2006 at 10:43:16AM +0100, Matthias Schmidt wrote:
>> Hi,
>>
>> * Markus Brueffer wrote:
>>> I have committed the patch to -CURRENT. I'll MFC it in about one week if
>>> nothing goes wrong.
>> Thanks for your work.  I've applied the patch to a 6.0-REL system
>> running on a Thinkpad T43 and the fan control works great :)
> 
> Dito on my T43p with 6.0-STABLE. Thanks a lot! One question though:
> Why is the default set to manual/fullspeed instead of automatically?
> Provided that without the patch, the behaviour would be equal to
> automatic mode, this breaks POLA and people might complain, or worse,
> send their thinkpads to Lenovo for repair, since they don't know
> why the fan is now constantly on full speed.

The current patch doesn't change the system default which obviously is
automatic mode. After further reading I discovered, that after boot, the
embedded controller register (which the driver exports via the sysctls)
may not reflect the true state of the embedded controller. On some
models it reads 0x07, which translates to: "manual mode with fan level
of 7", even though the embedded controller is actually in automatic
mode. This is what you are seeing.

I have created another patch which takes this into account and
explicitly sets the embedded controller register to enable automatic
mode and set level 0 for manual mode. Furthermore I have added code for
re-enabling automatic mode on unloading the module. You can find it here
(you need the first patch already applied):

http://people.freebsd.org/~markus/ibm/acpi_ibm.c.diff-2

Markus