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Date:   Wed, 26 Jul 2023 11:19:34 -0600
From:   Rob Herring <robh@kernel.org>
To:     Wesley Cheng <quic_wcheng@quicinc.com>
Cc:     agross@kernel.org, andersson@kernel.org,
        krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org,
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        linux-arm-kernel@lists.infradead.org, linux-usb@vger.kernel.org,
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Subject: Re: [PATCH v4 13/32] dt-bindings: usb: dwc3: Add
 snps,num-hc-interrupters definition
Message-ID: <20230726171934.GA1654540-robh@kernel.org>
References: <20230725023416.11205-1-quic_wcheng@quicinc.com>
 <20230725023416.11205-14-quic_wcheng@quicinc.com>
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On Mon, Jul 24, 2023 at 07:33:57PM -0700, Wesley Cheng wrote:
> Add a new definition for specifying how many XHCI secondary interrupters
> can be allocated.  XHCI in general can potentially support up to 1024
> interrupters, which some uses may want to limit depending on how many
> users utilize the interrupters.

Why does this belong in DT? What 'uses' determines the value? Who wants 
to change this and when?

> 
> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
> ---
>  .../devicetree/bindings/usb/snps,dwc3.yaml          | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
> index 50edc4da780e..cc6012e922e0 100644
> --- a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
> +++ b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
> @@ -376,6 +376,19 @@ properties:
>      items:
>        enum: [1, 4, 8, 16, 32, 64, 128, 256]
>  
> +  snps,num-hc-interrupters:
> +    description:
> +      Defines the maximum number of XHCI host controller interrupters that can
> +      be supported.  The XHCI host controller has support to allocate multiple
> +      event rings, which can be assigned to different clients/users.  The DWC3
> +      controller has a maximum of 8 interrupters.  If this is not defined then
> +      the value will be defaulted to 1.  This parameter is used only when
> +      operating in host mode.
> +    $ref: /schemas/types.yaml#/definitions/uint8
> +    minimum: 1
> +    maximum: 8
> +    default: 1
> +
>    port:
>      $ref: /schemas/graph.yaml#/properties/port
>      description: