Re: [PATCH RFC v2 03/10] dt-bindings: arm: Add MPAM MSC binding

[Andre Przywara]

Hi,

On 9/14/26 16:41, Andre Przywara wrote:
> Hi,
>
> On 9/14/26 11:37, Yin Li wrote:
> > From: Rob Herring <robh@xxxxxxxxxx>
> >
> > The binding is designed around the assumption that an MSC will be a
> > sub-block of something else such as a memory controller, cache 
> > controller,
> > or IOMMU. However, it's certainly possible a design does not have that
> > association or has a mixture of both, so the binding illustrates how 
> > we can
> > support that with RIS child nodes.
> >
> > A key part of MPAM is we need to know about all of the MSCs in the system
> > before it can be enabled. This drives the need for the genericish
> > 'arm,mpam-msc' compatible. Though we can't assume an MSC is accessible
> > until a h/w specific driver potentially enables the h/w.
> >
> > Cc: James Morse <james.morse@xxxxxxx>
> > Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
> > Signed-off-by: James Morse <james.morse@xxxxxxx>
> > Signed-off-by: Yin Li <yin.li@xxxxxxxxxxxxxxxx>
> > ---
> >   .../devicetree/bindings/arm/arm,mpam-msc.yaml      | 199 +++++++++++ 
> > ++++++++++
> >   1 file changed, 199 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/arm/arm,mpam-msc.yaml 
> > b/Documentation/devicetree/bindings/arm/arm,mpam-msc.yaml
> > new file mode 100644
> > index 000000000000..53a6fdbbf05f
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/arm/arm,mpam-msc.yaml
> > @@ -0,0 +1,199 @@
> > +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/arm/arm,mpam-msc.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Arm Memory System Resource Partitioning and Monitoring (MPAM)
> > +
> > +description: |
> > +  The Arm MPAM specification can be found here:
> > +
> > +  https://developer.arm.com/documentation/ddi0598/latest
> > +
> > +maintainers:
> > +  - Rob Herring <robh@xxxxxxxxxx>
> > +
> > +properties:
> > +  compatible:
> > +    items:
> > +      - const: arm,mpam-msc                   # Further details are 
> > discoverable
> > +      - const: arm,mpam-memory-controller-msc
>
> But that doesn't match the examples below, does it? Don't we want to 
> allow just "arm,mpam-msc", but also the memory controller string, with 
> "arm,mpam-msc" as a fallback?
> I guess the pattern should then look similar to interrupt-names below?

Just seeing that you fix this and other things up in patch 08/10 later.
I think it's confusing to have this split now for a v2 still. I wouldn't 
be aware of previous review of this original patch, so it doesn't really 
matter. Please squash them.

So I think you should merge 07/10 and 08/10 into their original patches, 
otherwise reviewers might just get confused.

But you might wait for a bit with a repost, to see if there are more 
generic comments on DT support.

Cheers,
Andre