Re: Nested suspends; messages vs. states

David Brownell
2005-03-24T05:31:01Z

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On Wednesday 23 March 2005 9:14 pm, Benjamin Herrenschmidt wrote:
>
> However, I'm wondering what will be the stack usage of such a model on
> deep bus layouts...

I've previously sketched algorithms that will linearize things.
It's what I referred to when I talked about dynamically building
the lists of devices to suspend or resume.

> > > The bridge driver largely don't exist (except for USB hubs), the
> > > requirements aren't very tough, and it would localize the semantics where
> > > they need to be - in the bus subsystems.
> >
> > Yes to localizing semantics!! Though as for requirements, that's
> > not always true.
>
> I don't agree with the bus subsystem beeing a good place here. I don't
> like it for lots of reasons and never liked it, because it totally lacks
> the notion of a bus "instance" among others... It's de-facto a device
> "bus type", so it's a "bus type" subsystem more than a "bus subsystem"
> imho. But careful explanation might still change my mind here.

Yes, there's bad terminology lurking. When I talk about a bus, I'm
rarely talkig about a "bus type" like PCI or USB ... I'm talking about
a specific instance. Strongly agreed that the relevant scope is an
instance ("just another device, with children") not a type/class.

- Dave