[coreboot] IT8716f FAN control [was: GeForce 8600GT with coreboot]

Ronald Hoogenboom ronald at zonnet.nl
Tue Feb 19 00:18:00 CET 2008

Hi Ward,

On Mon, 2008-02-18 at 17:07 -0500, Ward Vandewege wrote:
> On Mon, Feb 18, 2008 at 11:01:23PM +0100, Ronald Hoogenboom wrote:
> > I also noticed that the k8 powernow doesn't work:
> > 'powernow-k8: MP systems not supported by PSB BIOS structure' the kernel
> > says.
> Yeah - I always thought that was related to the lack of ACPI support.

How to tackle this issue? There are some boards that do have ACPI
support in coreboot, why not m57sli-s4?

> > On top of that, the vid voltage is set to 1.35V with coreboot (without
> > powernow) and to 1.10V (min. speed) - 1.30V (max. speed) booted with
> > proprietary bios (with powernow), which heats the processor even faster.
> How are you reading out those values? The lm-sensor code returns this stuff
> but a lot of it seems bogus - both under the proprietary bios and coreboot,
> and sometimes in different ways :)

I indeed use lm-sensors, and I would disagree that the values are bogus,
they just need to be taken with a grain of salt (or common sense with a
datasheet of the chip in question (it7816f)). Some values read depend on
the configuration of the EC part. Others (specifically the voltages)
depend on the external resistors used on the mainboard, these will not
change by using coreboot or any other bios. It would be handy if the
superiotool could dump this EC config too, so I can compare apples with
apples. But the vid just depends on 5 wires connected to the cpu and I
can see a direct linear relation between the vid decoded voltage value
and the measured core voltage, so the CPU indeed gets always at least 50
mV more than when powernow is active. And the 800RPM might not be the
exact RPM with the same division factor, but if it doesn't change, it
still means that the so-called 'SmartGuardian' regulation doesn't work.
The core temperature is read via the k8-temp module (temperature sensor
inside the CPU), which is not dependent on any config of the it8716f.

I think I'll go and extend superiotool... But not tonight.

> Thanks,
> Ward.

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