Re: [ibm-acpi-devel] Second fan on Thinkpad P50

[Matthias H. <mat...@tu...>]

Here is the latest version of my patch. I added quirks to recognize the
second fan and cleaned the code, any comments are welcome:
http://pastebin.com/eVPcnvfK

> From your patch, I understand the select_fan() thing we already have for the
> X60/X61 actually changes which fan is being controlled on the P50?

That is correct, the same mechanism/bit is used to select the active
fan. But there is some strange behavior when reading the status
register. Regardless of which fan is currently selected, the status
register always reads the status of fan1. This means I can set the fan
speed levels individually, but reading pwm2_enable or pwm2 always returns
the corresponding value of fan1.


> Otherwise, we can simply add a new quirk for second-fan-control-ok, and
> enable second-fan control only for the P50, and not for the X60/X61.

I added a quirk based on 'bios_model' (first two characters of BIOS
version), since the EC version is not read correctly by the module.

The Lenovo P70, which is very similar to the P50, shares these first
two characters 'N1' according to Lenovo's release notes, so it should
be automatically detected too. Some testing there is needed.
https://download.lenovo.com/pccbbs/mobiles/n1duj12w.txt

Regards,
Matthias