Re: [PATCH 2/2] powerpc: add support for MPIC message register API

[Scott Wood <scottwood-KZfg59tc24xl57MIdRCFDg@public.gmane.org>]

On Mon, 2 May 2011 09:03:53 -0700
Hollis Blanchard <hollis_blanchard-nmGgyN9QBj3QT0dZR+AlfA@public.gmane.org> wrote:

> On 05/01/2011 08:41 PM, Kushwaha Prabhakar-B32579 wrote:
> >> Perhaps an allocator could be added in the same patchset that adds such a
> >> user.
> > Yaa. It can be done. Otherwise module has to query each message unit for its availability.
> 
> No, instead the system designer should pick one. If it doesn't matter 
> which one, then the designer is free to pick any.

We should avoid resorting to the notion of a "system designer" if possible
-- it's hard to avoid it when dealing with partitioning, but it shouldn't
be needed for unpartitioned basic driver operation.

> An allocator can't work if you're going to mix drivers. For example, 
> driver A needs MSRG0, and driver B doesn't care. Driver B loads first, 
> the allocator selects MSGR0; driver A loads and fails. Having an 
> allocator at all will create this conflict.

In the absence of partitioning, no driver should need a specific one.  With
partitioning, let the system designer mark those resources as reserved so
they don't get allocated. :-)

-Scott