Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH] USB: serial: option: adding support for ublox R410M
To:     Johan Hovold <johan@kernel.org>
Cc:     =?UTF-8?Q?Bj=c3=b8rn_Mork?= <bjorn@mork.no>,
        =?UTF-8?B?U1ogTGluICjmnpfkuIrmmbop?= <sz.lin@moxa.com>,
        stable <stable@vger.kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        Dan Williams <dcbw@redhat.com>
References: <20180426062831.320-1-sz.lin@moxa.com>
 <20180426070927.GT4615@localhost>
 <72c63853-aa2d-e74c-1112-36d54ef52a85@gmail.com>
 <20180426081403.GA335@localhost> <87r2n25i6i.fsf@miraculix.mork.no>
 <3895ed90-bbb9-e7ce-34c0-a1654646cf83@gmail.com>
 <98b50ae7-b889-6811-476e-9cdc8a62a484@gmail.com>
 <20180426161228.GW4615@localhost>
From:   Lars Melin <larsm17@gmail.com>
Message-ID: <09866ede-25cf-3ca1-1be6-e720b4b5dd23@gmail.com>
Date:   Thu, 26 Apr 2018 23:22:25 +0700
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101
 Thunderbird/52.7.0
MIME-Version: 1.0
In-Reply-To: <20180426161228.GW4615@localhost>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 4/26/2018 23:12, Johan Hovold wrote:
> On Thu, Apr 26, 2018 at 06:40:46PM +0700, Lars Melin wrote:
>> On 4/26/2018 18:39, Lars Melin wrote:
>>> On 4/26/2018 18:19, Bjørn Mork wrote:
>>>> Anyway, Qualcomm based designs are definitely handled by both drivers.
>>>> Using qcserial only makes sense if the interface layout matches one of
>>>> the defined shared schemes, which currently are:
>>>>
>>>>      QCSERIAL_G2K = 0,    /* Gobi 2000 */
>>>>      QCSERIAL_G1K = 1,    /* Gobi 1000 */
>>>>      QCSERIAL_SWI = 2,    /* Sierra Wireless */
>>>>      QCSERIAL_HWI = 3,    /* Huawei */
>>>
>>> It seems to me that this Quectel device matches the interface layout for
>>> Gobi1K:
>>>
>>>            * Gobi 1K USB layout:
>>>            * 0: DM/DIAG (use libqcdm from ModemManager for communication)
>>>            * 1: serial port (doesn't respond)
>>>            * 2: AT-capable modem port
>>>            * 3: QMI/net
>>>            */
> 
>> Ublox, not Quectel..
> 
> Yeah, but qcserial appears to select a different altsetting for the DM
> port for Gobi 1000, an altsetting which this particular device does not
> have.
> 
> I didn't re-read the full thread I referred to earlier, but I think in
> it, Dan mentioned Gobi 1000 device requiring firmware to be loaded too.
> 
> So if it's not a G1K device, we probably shouldn't be using qcserial
> even if the interface layout happens to match.
> 
> Thanks,
> Johan

Good point, I forgot about the required firmware loading for Gobi1K.
So this device should be handled by the option driver.

/Lars