Message-ID: <05e55db1-5181-8025-8aee-e398200b047c@linaro.org>
Date:   Thu, 26 Jan 2023 13:01:44 +0100
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Subject: Re: [RFC PATCH v2 14/22] dt-bindings: usb: dwc3: Add
 snps,num-hc-interrupters definition
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To:     Wesley Cheng <quic_wcheng@quicinc.com>,
        srinivas.kandagatla@linaro.org, mathias.nyman@intel.com,
        perex@perex.cz, lgirdwood@gmail.com, andersson@kernel.org,
        krzysztof.kozlowski+dt@linaro.org, gregkh@linuxfoundation.org,
        Thinh.Nguyen@synopsys.com, broonie@kernel.org,
        bgoswami@quicinc.com, tiwai@suse.com, robh+dt@kernel.org,
        agross@kernel.org
Cc:     linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
        alsa-devel@alsa-project.org, devicetree@vger.kernel.org,
        linux-usb@vger.kernel.org, quic_jackp@quicinc.com,
        quic_plai@quicinc.com
References: <20230126031424.14582-1-quic_wcheng@quicinc.com>
 <20230126031424.14582-15-quic_wcheng@quicinc.com>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
In-Reply-To: <20230126031424.14582-15-quic_wcheng@quicinc.com>
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Precedence: bulk

On 26/01/2023 04:14, 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.

I cannot find in the code any user of this. Your next patch stores it,
but which other patch uses stored value?

What I still don't get how is this exactly hardware property, not policy
or driver choice.

> 
> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
> ---
>  Documentation/devicetree/bindings/usb/snps,dwc3.yaml | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
> index 6d78048c4613..4faaec9655e0 100644
> --- a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
> +++ b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
> @@ -349,6 +349,18 @@ 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:

Best regards,
Krzysztof