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Date:   Fri, 12 Jun 2020 10:02:11 -0400
From:   Alan Stern <stern@rowland.harvard.edu>
To:     Macpaul Lin <macpaul.lin@mediatek.com>
Cc:     Felipe Balbi <balbi@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org, Jim Lin <jilin@nvidia.com>,
        Siqi Lin <siqilin@google.com>,
        Mediatek WSD Upstream <wsd_upstream@mediatek.com>,
        Macpaul Lin <macpaul.lin@gmail.com>
Subject: Re: [PATCH] usb: replace hardcoded maximum usb string length by
 definition
Message-ID: <20200612140211.GA12639@rowland.harvard.edu>
References: <y>
 <1591939967-29943-1-git-send-email-macpaul.lin@mediatek.com>
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On Fri, Jun 12, 2020 at 01:32:47PM +0800, Macpaul Lin wrote:
> Replace hardcoded maximum usb string length (126 bytes) by definition
> "MAX_USB_STRING_LEN".
> 
> Signed-off-by: Macpaul Lin <macpaul.lin@mediatek.com>

...

> diff --git a/include/linux/usb.h b/include/linux/usb.h
> index 9f3c721..df4a9cb 100644
> --- a/include/linux/usb.h
> +++ b/include/linux/usb.h
> @@ -1815,6 +1815,8 @@ static inline int usb_get_ptm_status(struct usb_device *dev, void *data)
>  		0, data);
>  }
>  
> +/* USB String descriptors can contain at most 126 characters. */
> +#define MAX_USB_STRING_LEN	126

This definition belongs in include/uapi/linux/usb/ch9.h (near the 
definition of struct usb_string_descriptor) because it is part of the USB 
standard rather than specific to the Linux USB stack.

Alan Stern