Re: Changing temperature trip points

Dominik Brodowski
2002-11-03T20:16:07Z

On Sun, Nov 03, 2002 at 08:56:16PM +0100, Pavel Machek wrote:
> Hi!
>
> > I did in fact try that, and while it lets me change the values, they
> > don't actually seem to affect the kernel's idea of when the fan should
> > come on, if at all. I set the active trip point to 45 C and the passive
> > to 50 C, then ran a compile to see if the fan triggered. While the
> > temperature got above 50 C, the fan never came on. In fact, I don't
> > know if the fan would come on even if the originally-specified trip
> > points were reached. Either way, this isn't exactly the most comforting
> > situation to observe.
>
> That's because your fan is driven by hardware, not ACPI. I see it
> here, too. Passive cooling should work, through.

Actually, I think the problem is something else: The BIOS is supposed to
generate ACPI events whenever these trip points are reached. So if you
change these values (by patching the DSDT, by "hardwiring" it into the
kernel) you need to use the polling method. Then ACPI will compare the
current temperature to the specified temperatures with a specified
frequency. Any chance you can try whether my assuption is correct?

Dominik