Re: [PATCH 1/1] dt-bindings: net: snps,dwmac: Document queue config subnodes

[Krzysztof Kozlowski]

On 25/10/2022 10:17, Sebastian Reichel wrote:
> Hi,
> 
> On Mon, Oct 24, 2022 at 07:28:29PM -0400, Krzysztof Kozlowski wrote:
>> Old binding did not document "tx-queues-config". Old binding had
>> "snps,mtl-tx-config" which was a phandle, so this is an ABI break of
>> bindings.
>>
>> You are changing the binding - adding new properties.
> 
> The new binding still has the phandle. The only thing I changed is
> explicitly allowing the referenced node to be a subnode of the dwmac
> node. This is 100% compatible, since the binding does not specify
> where the referenced node should be. Only the example suggested it
> could be next to the ethernet node. But changing any properties in
> the config node means a ABI break requiring code changes.
> 
> Note, that right now 4/7 devicetrees with snps,mtl-tx-config already
> follow the scheme I documented. The other 3 have the queue config
> below the root node like the current example:
> 
> has the queues config in /:
>  * arch/arm/boot/dts/artpec6.dtsi
>  * arch/arm64/boot/dts/mediatek/mt2712e.dtsi
>  * arch/arm64/boot/dts/qcom/sa8155p-adp.dts
> 
> has the queues config in the ethernet node:
>  * arch/arm64/boot/dts/freescale/imx8mp-verdin.dtsi
>  * arch/arm64/boot/dts/freescale/imx8mp-evk.dts
>  * arch/arm64/boot/dts/rockchip/rk3568.dtsi
>  * arch/arm64/boot/dts/rockchip/rk356x.dtsi
> 
> After my change both are considered valid. Anyways I'm doing this
> for rk3588 and planned to follow the subnode style. But if I have
> to fully fix this mess I will just put the queue config to the
> root node instead and let somebody else figure this out.

Yeah, let it be.

Best regards,
Krzysztof