Re: [PATCH v9 01/10] dt-bindings: mmc: Document fixed-layout NVMEM provider support

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Using `fixed-layout` directly on the partition node merges the NVMEM provider and layout concepts, violating NVMEM architecture and breaking modern runtime layout parsing.
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--- Patch [1]: [PATCH v9 01/10] dt-bindings: mmc: Document fixed-layout NVMEM provider support ---
commit 9b7b4f5fdbeee58fc9a0bd8fb5f052592d78dc38
Author: Loic Poulain <loic.poulain@oss.qualcomm.com>

dt-bindings: mmc: Document fixed-layout NVMEM provider support

This commit allows an eMMC hardware partition node to describe an NVMEM
layout so the partition can be exposed as an NVMEM provider. It adds
fixed-layout as an accepted compatible string on the partition node.

> diff --git a/Documentation/devicetree/bindings/mmc/mmc-card.yaml b/Documentation/devicetree/bindings/mmc/mmc-card.yaml
> --- a/Documentation/devicetree/bindings/mmc/mmc-card.yaml
> +++ b/Documentation/devicetree/bindings/mmc/mmc-card.yaml
> @@ -38,7 +38,9 @@ patternProperties:
>      properties:
>        compatible:
>          contains:
> -          const: fixed-partitions
> +          enum:
> +            - fixed-partitions
> +            - fixed-layout

[Severity: High]
Does allowing fixed-layout directly on the partition node break the NVMEM
layout parser?

The NVMEM core's modern layout parser, nvmem_add_cells_from_fixed_layout(),
calls of_nvmem_layout_get_container(). This function hardcodes a lookup for
a child node exactly named "nvmem-layout".

If the layout is placed directly on the partition node rather than in a child
node, this lookup returns NULL and parsing silently aborts, preventing the
NVMEM cells from registering.

[ ... ]

> @@ -86,6 +88,25 @@ examples:
>                      read-only;
>                  };
>              };
> +
> +            partitions-boot2 {
> +                compatible = "fixed-layout";

[Severity: High]
Will the NVMEM cells defined under this example silently fail to register at
runtime?

Because there is no nvmem-layout child node, applying the fixed-layout
compatible directly to the partition node merges the provider and layout
concepts. This violates the NVMEM architecture expected by the parser.

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Sashiko AI review · https://sashiko.dev/#/patchset/20260730-block-as-nvmem-v9-0-f72935817dbf@oss.qualcomm.com?part=1