Re: [RFC][PATCH] PM: Make power domain callbacks take precedence over subsystem ones

From: Rafael J. Wysocki
Date: Fri Apr 15 2011 - 19:18:34 EST

On Friday, April 15, 2011, Alan Stern wrote:
> On Fri, 15 Apr 2011, Rafael J. Wysocki wrote:
> > On Thursday, April 14, 2011, Magnus Damm wrote:
> > > My only thought on this is if we really want to limit ourselves to
> > > only control power domains using these callbacks. I can imagine that
> > > some SoCs want to do other non-power domain specific operations with
> > > these callbacks, and if so, perhaps using the term power domain as
> > > name of the pointer in struct device would be somewhat odd. OTOH, I
> > > really dislike naming discussions in general and I can't really think
> > > of any good names. So it all looks more like a set of system specific
> > > PM override hooks.
> > >
> > > Or is there something that is really power domain specific with these hooks?
> >
> > Not in principle, but I think there is. Namely, if there are two groups
> > of devices belonging to the same bus type (e.g. platform) that each require
> > different PM handling, it is legitimate to call them "power domains" (where
> > "domain" means "a set of devices related to each other because of the way
> > they need to be handled"), even if they don't share power resources.
> >
> > Of course, if they do share power resources, the term is just right. :-)
> They could be called "PM domains" instead of "power domains". That's
> legitimate because they do get used by the PM core, even if they don't
> literally involve groups of devices sharing the same power supply.

Well, "power domain" can be regarded as a short form of "power management
domain", which makes the point kind of moot. ;-)


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