Re: [PATCH] acpi: move thermal trip handling to generic thermal layer

[Thomas Renninger <trenn@suse.de>]

On Wednesday 17 December 2008 04:12:15 Matthew Garrett wrote:
> On Wed, Dec 17, 2008 at 11:02:18AM +0800, Zhang Rui wrote:
> > On Mon, 2008-12-08 at 20:59 +0800, Matthew Garrett wrote:
> > > They're needed if you want to implement any sort of sensible
> > > implementation of passive cooling. They might not be expressed in quite
> > > the same way, but the basic concept is identical.
> >
> > Seeing tc1, tc2, tsp under /sys/class/thermal/ is not good because we
> > don't want to make the generic thermal driver too ACPI specific, before
> > we've really concluded some basic concepts for passive cooling.
> > so why not do this after we have another generic thermal user with
> > passive cooling support?
>
> They're not exposed in /sys/class, and I don't think doing so is a
> sensible thing to do. If you know values for the hardware in question
> then they should be supplied by the firmware. But even so, the generic
> thermal layer needs a way of implementing passive cooling. Doing so
> involves deriving a formula to describe the behaviour of the system
> around the passive trip level, and the best used implementation of that
> in Linux at the moment is the one described in the ACPI spec. I don't
> see any real need to generate new terms to describe well documented
> concepts, even if other implementations don't use ACPI.

If others need a specific algorithm, another (set of) callback function(s)
could be added later which would provide the possibility of
a platform specific override?

     Thomas