[PATCH RFC v2 1/5] dt-bindings: display: panel: Fix port binding

[Krzysztof Kozlowski]

On Thu, Apr 24, 2025 at 05:07:39PM GMT, Kory Maincent wrote:
> Faced a binding error check while adding the data-lanes property in the
> ilitek,ili9881c binding. See the next patch for the binding changes.
> Here is the error:
> Documentation/devicetree/bindings/display/panel/ilitek,ili9881c.example.dtb:
> panel at 0: port:endpoint: Unevaluated properties are not allowed
> ('data-lanes' was unexpected)

There is no error at this point so your rationale is not correct. You
cannot use possible error as reason to fix something... You can use
instead other arguments that the binding is incomplete or incorrect.

> 
> Change the reference of properties/port to $defs/port-base to makes it
> work.
> The only difference between port and port-base is the unevaluatedProperty
> set to false. I have tried to use properties/port in both panel-common
> and ilitek,ili9881c bindings but the error is still there. The only way
> to not face the error is to use $defs/port-base reference. I don't
> really understand the ins and outs, maybe it is a issue from the binding
> check tool.
> 
> Signed-off-by: Kory Maincent <kory.maincent at bootlin.com>
> ---
> 
> Changes in v2:
> - New patch
> ---
>  Documentation/devicetree/bindings/display/panel/panel-common.yaml | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/display/panel/panel-common.yaml b/Documentation/devicetree/bindings/display/panel/panel-common.yaml
> index 087415753d606ce67bceabaa9b0ba7d463282f92..635f67ced0cb7103684a1415ab740d83409a7dbb 100644
> --- a/Documentation/devicetree/bindings/display/panel/panel-common.yaml
> +++ b/Documentation/devicetree/bindings/display/panel/panel-common.yaml
> @@ -76,7 +76,7 @@ properties:
>  
>    # Connectivity
>    port:
> -    $ref: /schemas/graph.yaml#/properties/port
> +    $ref: /schemas/graph.yaml#/$defs/port-base

This allows anything in the port in every other binding, so is not
correct. You need to fully describe the port here with
additionalProps:false, probably. Just like every other binding with
port-base is doing.


Best regards,
Krzysztof