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Subject: Re: [PATCH] option: Do not try to bind to ADB interfaces
To:     Romain Izard <romain.izard.pro@gmail.com>,
        Johan Hovold <johan@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        stable <stable@vger.kernel.org>
References: <20180723140220.7166-1-romain.izard.pro@gmail.com>
From:   Lars Melin <larsm17@gmail.com>
Message-ID: <73f2233a-cafd-a477-0c0a-260be832777d@gmail.com>
Date:   Mon, 23 Jul 2018 22:15:03 +0700
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On 7/23/2018 21:02, Romain Izard wrote:
> Some modems now use the Android Debug Bridge to provide a debugging
> interface, and some phones can also export serial ports managed by the
> "option" driver.
> 
> The ADB daemon running in userspace tries to use USB interfaces with
> bDeviceClass=0xFF, bDeviceSubClass=0x42, bDeviceProtocol=1
> 
> Prevent the option driver from binding to those interfaces, as they
> will not be serial ports.

You are assuming that an interface with these attributes are always a
ADB interface - that is wrong. Vendor specific class (0xff) is not
standardized to be something specific.


> This can fix issues like:
> https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=781256
> 

You are trying to solve a 4++ years old bug report where it was assumed 
that the option driver was the culprit. The device in question, a 
Qualcomm modem with vid/pid 05c6:9025 has never been included in option.


rgds
Lars