Re: [PATCH v6 1/2] dt-bindings: dma: snps,dw-axi-dmac: Add fallback compatible for CV1800B

Conor Dooley <[email protected]> Mon, 11 May 2026 17:01:01 +0100
Newsgroups dev.linux.lists.sophgo,org.infradead.lists.linux-riscv,org.kernel.vger.dmaengine,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-kernel
Message-ID <20260511-crave-sworn-3b43371ce11a@spud>
On Mon, May 11, 2026 at 02:38:16PM +0800, Inochi Amaoto wrote:
> The previous version of the binding change only add compatible
> string without adding the fallback compatible, this breaks
> backward compatibility. Add the needed fallback compatible to
> fix this.

I don't understand how adding a specific comaptible affected backwards
compatibility. Did the dts originally use the snps compatible before the
device specific one was added?

> 
> Fixes: be3e2a0419c6 ("dt-bindings: dma: snps,dw-axi-dmac: Add CV1800B compatible")
> Signed-off-by: Inochi Amaoto <[email protected]>
> ---
>  Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml b/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml
> index 804514732dbe..0a30a455b0ee 100644
> --- a/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml
> +++ b/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml
> @@ -21,11 +21,12 @@ properties:
>        - enum:
>            - snps,axi-dma-1.01a
>            - intel,kmb-axi-dma
> -          - sophgo,cv1800b-axi-dma
>            - starfive,jh7110-axi-dma
>            - starfive,jh8100-axi-dma
>        - items:
> -          - const: altr,agilex5-axi-dma
> +          - enum:
> +              - altr,agilex5-axi-dma
> +              - sophgo,cv1800b-axi-dma
>            - const: snps,axi-dma-1.01a
>  
>    reg:
> -- 
> 2.54.0
>
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