Re: [PATCH 1/5] xen: arm: propagate gic's #address-cells property to dom0.

[Ian Campbell <Ian.Campbell@citrix.com>]

On Wed, 2014-10-29 at 19:03 +0000, Julien Grall wrote:
> Hi Ian,
> 
> On 24/10/2014 10:58, Ian Campbell wrote:
> > The interrupt-map property requires that the interrupt-parent node
> > must have both #address-cells and #interrupt-cells properties (see
> > ePAPR 2.4.3.1). Therefore propagate the property if it is present.
> >
> > We must propagate (rather than invent our own value) since this value
> > is used to size fields within other properties within the tree.
> >
> > ePAPR strictly speaking requires that the interrupt-parent node
> > always has these properties. However reality has diverged from this
> > and implementations will recursively search parents for #*-cells
> > properties. Hence we only copy if it is present.
> >
> > Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
> 
> Reviewed-by: Julien Grall <julien.grall@linaro.org>
> 
> Without this patch I can't boot Xen on the Foundation model with GIC-v3. 
> Is it possible to push this patch for Xen 4.5 rc1?

Konrad, I think this is needed for 4.5 since without it dom0 can fail to
parse certain other constructs within the DT (in bits which we don't
generate and can't easily/don't want to rewrite as we pass them
through).

The risk is that some bit of DT which we do generate relies on this
value being absent (as it was before this patch). I don't believe we
generate any such nodes. The consumers are typically nodes representing
devices which we pass through rather than messing with them.

Ian.