Drivers for cellular modems

[Dan Williams]

On Mon, 2018-04-16 at 16:14 +0200, Bjørn Mork wrote:
> Don't make things more complicated than necessary.  Boot Linux and it
> will figure this out for you.

To expand a bit on Bjorn's reply, the kernel looks at the device's USB
descriptors and will choose the matching driver automatically.  So if
the USB device itself advertises MBIM functionality, then the kernel
will choose cdc_mbim.  If the device matches known QMI USB layouts,
then the kernel will choose qmi_wwan.

Both qmi_wwan and cdc_mbim can be loaded at the same time, driving
different devices.

For your last question, many devices support multiple USB layouts in
the same device, but require an explicit switch command to change
whether they expose QMI, MBIM, or AT/etc to the host computer.

Dan

> 
> Bjørn
> 
> Pavlin Georgiev <pavlin at varna.net> writes:
> 
> > Hi,
> > 
> > I have a testing machine with modem Sierra Wireless EM7455.
> > Which drivers should be used:
> > A) qmi_wwan
> > B) cdc_mbim
> > 
> > Are these drivers compatible? Can they be loaded together on a
> > system XOR they are excluding each other?
> > 
> > In the documentation from the manufacturer, it is clear that:
> > 
> > The device supports the following protocols for modem
> > communication:
> > 
> >   * Qualcomm QMI interface. (Please contact your Sierra Wireless
> > account representative for QMI interface documentation.)
> >   * MBIM (Mobile Broadband Interface Model)
> > 
> > Thank you for your advice.
> > Pavlin
> > 
> > _______________________________________________
> > libqmi-devel mailing list
> > libqmi-devel at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/libqmi-devel
> 
> _______________________________________________
> libqmi-devel mailing list
> libqmi-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/libqmi-devel