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Date:   Mon, 8 Feb 2021 20:30:35 -0600
From:   Rob Herring <robh@kernel.org>
To:     Howard Yen <howardyen@google.com>
Cc:     gregkh@linuxfoundation.org, mathias.nyman@intel.com,
        linux-usb@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 4/4] dt-bindings: usb: usb-xhci: add USB offload support
Message-ID: <20210209023035.GA2552083@robh.at.kernel.org>
References: <20210119101044.1637023-1-howardyen@google.com>
 <20210119101044.1637023-5-howardyen@google.com>
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On Tue, Jan 19, 2021 at 06:10:44PM +0800, Howard Yen wrote:
> Document USB offload support for usb-xhci.

Is this a standard XHCI capability or specific to certain 
implementations? Do all versions of DWC3 support it?

> 
> For example:
> 
> &usbdrd_dwc3 {
> 	...
> 	/* support usb offloading, 0: disabled, 1: audio */
> 	offload = <1>;
> 	...
> };
> 
> Signed-off-by: Howard Yen <howardyen@google.com>
> ---
>  Documentation/devicetree/bindings/usb/usb-xhci.txt | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/Documentation/devicetree/bindings/usb/usb-xhci.txt b/Documentation/devicetree/bindings/usb/usb-xhci.txt
> index b120dd6612a2..aab1fd499f15 100644
> --- a/Documentation/devicetree/bindings/usb/usb-xhci.txt
> +++ b/Documentation/devicetree/bindings/usb/usb-xhci.txt
> @@ -46,6 +46,7 @@ Optional properties:
>    - quirk-broken-port-ped: set if the controller has broken port disable mechanism
>    - imod-interval-ns: default interrupt moderation interval is 5000ns
>    - phys : see usb-hcd.yaml in the current directory
> +  - offload: supporting USB offload feature, 0: disabled, 1: audio

What does not present mean? Unless you need 'keep the h/w default', then 
this can be boolean instead.

>  
>  additionally the properties from usb-hcd.yaml (in the current directory) are
>  supported.
> -- 
> 2.30.0.284.gd98b1dd5eaa7-goog
>