[PATCH 2/3] Use embedded libfdt in the bootwrapper
David Gibson
david at gibson.dropbear.id.au
Tue Dec 11 10:32:25 EST 2007
On Mon, Dec 10, 2007 at 05:19:02PM -0600, Scott Wood wrote:
> David Gibson wrote:
> > On Mon, Dec 10, 2007 at 11:32:17AM -0600, Scott Wood wrote:
> >> How does using offsets as devps work if a devp was previously
> >> acquired to a node that has to be moved due to a change later made
> >> in an earlier part of the tree?
> >
> > It doesn't; don't do that. I just don't think truly persistent
> > phandles are worth the code complexity to implement them.
>
> We already have working code to implement them. This is a regression
> over flatdevicetree.c, and it (or something else in libfdt) seems to be
> breaking the ep8248e wrapper (it didn't make it in to the last window
> because of dependency on a netdev patch, but I'll probably send it out
> tomorrow).
>
> It breaks the extremely common and useful usage of:
>
> devp = create node;
> setprop(devp, "foo", something);
> setprop(devp, "bar", something);
Uh.. no, that idiom is fine. setprop() in the node itself, or any
descendent is guaranteed to be safe.
>
> > Especially since their use more-or-less completely precludes libfdt's
> > "stateless" approach, which has significant other advantages.
>
> It doesn't preclude stateless read-only -- what are the benefits to
> stateless read-write that are worth invalidating all node references any
> time something changes?
It precludes stateless read-only too, unless you have an interface
where devps for read-write are different from those for read-only
which would be nasty.
--
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
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