Re: [PATCH] net: qmi_wwan: add Dell DW5818, DW5819

From: Shrirang Bagul
Date: Mon Nov 20 2017 - 05:01:39 EST


On Mon, 2017-11-20 at 10:41 +0100, BjÃrn Mork wrote:
> Shrirang Bagul <shrirang.bagul@xxxxxxxxxxxxx> writes:
>
> > Dell Wireless 5819/5818 devices are re-branded Sierra Wireless MC74
> > series modems which will by default boot with vid 0x413c and pid's
> > 0x81cf, 0x81d0, 0x81d1,0x81d2. Along with qcserial, these modems support
> > qmi_wwan on the usb interface #12.
>
> NAK,
>
> Interace #12 is MBIM, as shown by the device descriptors. Please provide
> those descriptors and you will see that this interface is clearly a CDC
> MBIM class interface.
>
> Yes, I know these modems probe the control protocol so that you can make
> QMI work on an MBIM control interface by sending it a QMI request as the
> first messsage. This is still wrong, abusing a quirky firmware
> feature.
>
> You need to reconfigure the modem for QMI using the Sierra specific AT
> command or QMI request (tunneled in MBIM!) to properly switch it to QMI
> mode, which will appear as a vendor specific interface number 8 (and 10
> if you enable both QMI functions).
Understood. Needs more work, will resend with fixes.

- Shrirang
>
>
>
>
>
> BjÃrn

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