Subject: Re: [PATCH 15/16] Add device tree for Ebony

From: David Gibson <[email-masked]>
Date: Wed, 14 Feb 2007 15:46:41 +1100

On Wed, Feb 14, 2007 at 12:51:06PM +1100, Benjamin Herrenschmidt wrote:
> 
> > > > +	UIC0: interrupt-controller { /* UIC0 */
> > > 
> > > > +		#address-cells = <0>;
> > > > +		#size-cells = <0>;
> > > 
> > > #address-cells = 0 never makes sense.
> > 
> > Why not?  Children of this node have and need no reg property, and no
> > meaningful address.  Sounds like #address-cells = 0 to me.
> 
> In fact, not only it does make perfect sense but it's also routinely
> used for ... interrupt controllers :-) That's among others why the
> interrupt map entries "second" part usually doesn't contain the address
> cells.

Oh, btw, I take it you didn't think my method of placing the secondary
UICs under the node for UIC0 was insane.

> > > > +	plb {
> > > > +		device_type = "soc";
> > > > +		compatible = "ibm,plb-440gp", "ibm,plb4";
> > > > +		ranges;
> > > 
> > > You need a #address-cells, #size-cells here.
> > 
> > Why?  The values inherited from the root node are perfectly ok here.
> 
> Inheriting values is out of spec. The kernel somewhat does it but that's
> a bad habit, we should always have them explicit.

Ah, ok.  Values added.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson