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From:   Kristian Evensen <kristian.evensen@gmail.com>
Date:   Wed, 12 Sep 2018 18:57:57 +0200
Message-ID: <CAKfDRXi3QdB0qCvqHPFXpxdpiHSJ2WoSqZGgjD3gEzAaPbBPUQ@mail.gmail.com>
Subject: Re: [PATCH] option: Improve Quectel EP06 detection
To:     Lars Melin <larsm17@gmail.com>
Cc:     Johan Hovold <johan@kernel.org>, linux-usb@vger.kernel.org,
        linux-kernel@vger.kernel.org
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On Wed, Sep 12, 2018 at 6:32 PM Lars Melin <larsm17@gmail.com> wrote:
> You have chosen a platform which has limited usb resources and want to
> solve that problem by adjusting the device driver?

No, you asked for a good reason for why disabling and not just
ignoring an interface makes sense, and I think that supporting
multiple EP06 on platforms with limited endpoints qualifies as a
reason. My motivation behind this patch and modifying the driver, is
to make the driver work with the different options/combinations
supported by the modem. The platforms I am working on merely triggered
the error and inspired the change.

> Why don't you just unbind those interfaces which you are not using and
> which are eating up your usb resources?

As far as I know, unbinding interfaces from the driver does not free
up the memory allocated to the interface by/on the USB controller. I
also tried, just in case, and the output from lsusb is the same
regardless of bind/unbind.

Btw, the patch for the QMI driver has been accepted, since you
mentioned that driver earlier. So the assumption about interface four
is removed from there.

BR,
Kristian