[PATCH 15/16] Add device tree for Ebony
Benjamin Herrenschmidt
benh at kernel.crashing.org
Wed Feb 14 12:51:06 EST 2007
> > > + 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.
> > > + 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.
Ben.
More information about the Linuxppc-dev
mailing list