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

[Inochi Amaoto <inochiama@gmail.com>]

On Mon, May 11, 2026 at 05:01:01PM +0100, Conor Dooley wrote:
> 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?
> 

Yes, the device is already in DTS, and since I find an quirk for
it. A new compatible with fallback is necessary.

Regards,
Inochi

> > 
> > Fixes: be3e2a0419c6 ("dt-bindings: dma: snps,dw-axi-dmac: Add CV1800B compatible")
> > Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
> > ---
> >  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
> >