Re: community PM requirements/issues and PowerOP [Was: Re: So, what's the status on the recent patches here?]

Pavel Machek
2006-09-11T21:39:30Z

On Mon 2006-09-11 17:36:33, Preece Scott-PREECE wrote:
>
> > From: Pavel Machek [mailto:pavel@ucw.cz]
> >
> > > >>- PowerOP is only one layer (towards the bottom) in a power
> > > >>management solution.
> > > >>- PowerOP does *not* replace cpufreq
> > > >
> > > >PowerOP provides userland interface for changing processor
> > frequency.
> > > >That's bad -- duplicate interface.
> > > Basically the biggest problem with cpufreq interface is
> > that cpufreq
> > > has "chose predefined closest to a given frequency" functionality
> > > implemented in the kernel while there is _no_ any reason to
> > have this
> > > functionality implemented in the kernel if we have sysfs interface
> > > exported by PowerOP in place - you just
> >
> > No, there is reason to keep that in kernel -- so that cpufreq
> > userspace interface can be kept, and so that resulting
> > kernel<->user interface is not ugly.
> ---
>
> Just as a data point, "keeping the cpufreq interface" is
> irrelevant to a number of us, because we configure it out
> of the system. I'm not really arguing that we should get
> rid of an existing kernel interface, but I don't see any
> reason why we shouldn't be able to have a separately
> configurable interface if cpufreq doesn't meet our needs.

Configurable interfaces are evil, and I do not think you can push such
patch. You have developed your own little interface that suits your
needs -- and that's fine -- but now you are trying to push it into
mainline... and that is not, because those interfaces were not really
designed to work together.
Pavel
--
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