Re: [PATCH 1/1] dt-bindings: net: mdio: Add negative patten match for child node

[Rob Herring <robh@kernel.org>]

On Sun, Aug 11, 2024 at 11:11:14PM -0400, Frank Li wrote:
> mdio.yaml wrong parser mdio controller's address instead phy's address when
> mdio-mux exist.
> 
> For example:
> mdio-mux-emi1@54 {
> 	compatible = "mdio-mux-mmioreg", "mdio-mux";
> 
>         mdio@20 {
> 		reg = <0x20>;
> 		       ^^^ This is mdio controller register
> 
> 		ethernet-phy@2 {
> 			reg = <0x2>;
>                               ^^^ This phy's address
> 		};
> 	};
> };
> 
> Only phy's address is limited to 31 because MDIO bus defination.
> 
> But CHECK_DTBS report below warning:
> 
> arch/arm64/boot/dts/freescale/fsl-ls1043a-qds.dtb: mdio-mux-emi1@54:
> 	mdio@20:reg:0:0: 32 is greater than the maximum of 31
> 
> The reason is that "mdio@20" match "patternProperties: '@[0-9a-f]+$'" in
> mdio.yaml.
> 
> Change to '^(?!mdio@).*@[0-9a-f]+$' to avoid match parent's mdio
> controller's address.
> 
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---
>  Documentation/devicetree/bindings/net/mdio.yaml | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/net/mdio.yaml b/Documentation/devicetree/bindings/net/mdio.yaml
> index a266ade918ca7..a7def3eb4674d 100644
> --- a/Documentation/devicetree/bindings/net/mdio.yaml
> +++ b/Documentation/devicetree/bindings/net/mdio.yaml
> @@ -59,7 +59,7 @@ properties:
>      type: boolean
>  
>  patternProperties:
> -  '@[0-9a-f]+$':
> +  '^(?!mdio@).*@[0-9a-f]+$':

This is at the wrong spot. The problem is up a level where the $nodename 
matched mdio-mux-emi1@54.

I think what we want for the $nodename pattern is:

'^mdio(-(bus|external))?(@.+|-([0-9]+))$'

There's lots of pinctrl nodes named 'mdio...' we need to avoid and we 
aren't currently.

I'd prefer not to support 'mdio-external', but there's already 1 
documented case. I think the only node name fix we'd need with this is 
'mdio-gpio' which should be just 'mdio' or 'mdio-N' like all other 
bitbanged implementations.

Rob