Re: [PATCH] dt-bindings: drm/bridge: Update reg-name list for cdns,mhdp8546 compatible

[Krzysztof Kozlowski <krzk@kernel.org>]

On 07/11/2025 14:15, Harikrishna Shenoy wrote:
> Remove j721e-intg register name from reg-name list for cdns,mhdp8546
> compatible. The j721e-intg registers are specific to TI SoCs, so they
> are not required for compatibles other than ti,j721e-mhdp8546.
> 
> Move the register name constraints to the appropriate compatibility
> sections to ensure the correct register names are used with each
> compatible value.
> 
> Fixes: 7169d082e7e6 ("dt-bindings: drm/bridge: MHDP8546 bridge binding changes for HDCP")
> Signed-off-by: Harikrishna Shenoy <h-shenoy@ti.com>
> ---
> 
> Links to some discussions pointing to need for a fixes patch: 
> https://lore.kernel.org/all/20250903220312.GA2903503-robh@kernel.org/
> https://lore.kernel.org/all/d2367789-6b54-4fc2-bb7c-609c0fe084d3@ti.com/
> 
>  .../bindings/display/bridge/cdns,mhdp8546.yaml      | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/display/bridge/cdns,mhdp8546.yaml b/Documentation/devicetree/bindings/display/bridge/cdns,mhdp8546.yaml
> index c2b369456e4e2..2fdb4f7108ed5 100644
> --- a/Documentation/devicetree/bindings/display/bridge/cdns,mhdp8546.yaml
> +++ b/Documentation/devicetree/bindings/display/bridge/cdns,mhdp8546.yaml
> @@ -30,10 +30,6 @@ properties:
>  
>    reg-names:
>      minItems: 1
> -    items:
> -      - const: mhdptx
> -      - const: j721e-intg
> -      - const: mhdptx-sapb
>  
>    clocks:
>      maxItems: 1
> @@ -103,7 +99,10 @@ allOf:
>            maxItems: 3
>          reg-names:
>            minItems: 2
> -          maxItems: 3
> +          items:
> +            - const: mhdptx
> +            - const: j721e-intg
> +            - const: mhdptx-sapb
>      else:
>        properties:
>          reg:
> @@ -111,7 +110,9 @@ allOf:
>            maxItems: 2
>          reg-names:
>            minItems: 1
> -          maxItems: 2
> +          items:
> +            - const: mhdptx
> +            - const: mhdptx-sapb

This does not match regs now. Look which entry is the second - it is
always DSS_EDP0_INTG_CFG_VP.

Optional item should be the last, not the middle. That's why DT
maintainers ask (and it is even documented) to post complete bindings.
Complete means all registers, entire address space.

Best regards,
Krzysztof