Date:   Tue, 28 Feb 2023 09:37:52 -0600
From:   Rob Herring <robh@kernel.org>
To:     Walker Chen <walker.chen@starfivetech.com>
Cc:     Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>,
        Vinod Koul <vkoul@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor.dooley@microchip.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Emil Renner Berthing <emil.renner.berthing@canonical.com>,
        dmaengine@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org
Subject: Re: [PATCH v3 1/3] dt-bindings: dma: snps,dw-axi-dmac: constrain
 minItems/maxItems of resets for JH7110 DMA
Message-ID: <20230228153752.GA3292255-robh@kernel.org>
References: <20230227131042.16125-1-walker.chen@starfivetech.com>
 <20230227131042.16125-2-walker.chen@starfivetech.com>
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On Mon, Feb 27, 2023 at 09:10:40PM +0800, Walker Chen wrote:
> The DMA controller needs two reset items to work properly on JH7110 SoC,
> so there is need to change the maxItems' value to 2 and add minItems
> whose value is equal to 1. Other platforms do not have this constraint.
> 
> Signed-off-by: Walker Chen <walker.chen@starfivetech.com>
> ---
>  .../bindings/dma/snps,dw-axi-dmac.yaml        | 25 ++++++++++++++++---
>  1 file changed, 21 insertions(+), 4 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml b/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml
> index ad107a4d3b33..4ed0a6b7ca69 100644
> --- a/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml
> +++ b/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml
> @@ -12,14 +12,12 @@ maintainers:
>  description:
>    Synopsys DesignWare AXI DMA Controller DT Binding
>  
> -allOf:
> -  - $ref: "dma-controller.yaml#"
> -
>  properties:
>    compatible:
>      enum:
>        - snps,axi-dma-1.01a
>        - intel,kmb-axi-dma
> +      - starfive,jh7110-axi-dma
>  
>    reg:
>      minItems: 1
> @@ -58,7 +56,8 @@ properties:
>      maximum: 8
>  
>    resets:
> -    maxItems: 1
> +    minItems: 1
> +    maxItems: 2
>  
>    snps,dma-masters:
>      description: |
> @@ -109,6 +108,24 @@ required:
>    - snps,priority
>    - snps,block-size
>  
> +allOf:
> +  - $ref: "dma-controller.yaml#"
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            enum:
> +              - starfive,jh7110-axi-dma
> +    then:
> +      properties:
> +        resets:
> +          minItems: 1
> +          maxItems: 2

A given platform should not have a variable number of resets. This also 
does nothing because you just duplicated the top-level constraints. If 
you have 2, then you want just 'minItems: 2'.

Rob