Re: "memory" binding issues

From: Benjamin Herrenschmidt
Date: Mon Sep 16 2013 - 21:37:50 EST


On Mon, 2013-09-16 at 16:48 -0700, Olof Johansson wrote:
> On Mon, Sep 16, 2013 at 4:47 PM, Benjamin Herrenschmidt
> <benh@xxxxxxxxxxxxxxxxxxx> wrote:
> > On Mon, 2013-09-16 at 15:48 -0700, Olof Johansson wrote:
> >> > A node that has a "reg" property should have the corresponding unit
> >> > address.
> >>
> >> No, absolutely _NOT_ a requirement. Unit address is only required if
> >> needed to disambiguate two properties with the same name.
> >>
> >> If there are no ambiguities, then leaving off the unit address is much
> >> preferred.
> >
> > I disagree :-)
>
> Well, good thing you've got your own arch to litter the device trees
> with unit specifiers in then. :)

Right :-) We tend to have multiple memory nodes on server anyway so it's
not a big deal.

> > Also this would be only true of our find_node_by_path was capable of
> > handling it, which it isn't. Thus you end up with generic code looking
> > for /memory and finding nothing ...
>
> Yes, this should be fixed.

Right, the whole thing becomes mostly a non-issue once that's fixed. My
main objection isn't that ARM doesn't use unit address specifiers. My
objection is that the binding documents no unit address :-) It should
instead document the unit address with a note indicating that it can be
omitted if there is no ambiguity.

But first, do we have a volunteer to fix the path parsing code ? Also do
we *really* need to keep the path parsing code for fdt ? IE. It would be
annoying to have to duplicate that code for before and after
expansion...

Cheers,
Ben.

> -Olof
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