Subject: Re: [PATCH v2 3/4] dt-bindings: net: realtek,rtl82xx: add a property to set MDI polarity

From: Rob Herring <[email-masked]>
Date: Thu, 22 Jan 2026 10:51:02 -0600

On Wed, Jan 21, 2026 at 04:15:05PM +0100, Damien Dejean wrote:
> MDI pair polarity is usually configured by the bootloader.  However, on
> some designs the configuration is left untouched during boot and needs
> to be set by the driver.
> 
> Add the property 'realtek,mdi-cfg-polarity' to configure the polarity of
> each pair. Bit 0 to 3 configure the polarity or pairs A to D, if set to
> 1 the polarity is reversed for this pair.
> 
> Signed-off-by: Damien Dejean <[email-masked]>
> ---
>  Documentation/devicetree/bindings/net/realtek,rtl82xx.yaml | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/net/realtek,rtl82xx.yaml b/Documentation/devicetree/bindings/net/realtek,rtl82xx.yaml
> index c4ced671ecb8..17088c147358 100644
> --- a/Documentation/devicetree/bindings/net/realtek,rtl82xx.yaml
> +++ b/Documentation/devicetree/bindings/net/realtek,rtl82xx.yaml
> @@ -61,6 +61,13 @@ properties:
>      description:
>        Force normal (0) or reverse (1) order of MDI pairs.
>  
> +  realtek,mdi-cfg-polarity:
> +    description:
> +      A bitmap to describe pair polarity swap. Bit 0 to swap polarity of pair A,
> +      bit 1 to swap polarity of pair B, bit 2 to swap polarity of pair C and bit
> +      3 to swap polarity of pair D.
> +    $ref: /schemas/types.yaml#/definitions/uint32

maximum: 0xf

However, are these properties something that should be common?

Rob