Re: Gobi 3000 (1199:901F)

[Bjørn Mork <bjorn mork no>]

Dan Williams <dcbw redhat com> writes:
> On Thu, 2015-01-29 at 10:24 -0500, Jeremy Moles wrote:
> > I'm working on testing this patch, but something else funny is 
> > occurring. I can no longer actually query the device using qmicli 
> > anymore under any condition... every attempt times out or returns:
> >
> > [29 Jan 2015, 10:23:06] -Warning ** [/dev/cdc-wdm0] QMI framing error 
> > detected
> >
> > I will try and resolve these and get you an answer.
> >
> > Also: the code you added in qmi_wwan never even gets evaluated AT ALL 
> > until I switch the device into the mode (via the sysfs echo) that 
> > exposes the serial ports; does that sound backwards to you, too?
>
> That sounds odd; is your device driven by MBIM or QMI here?  At least on
> most Sierra devices with either DirectIP or QMI support, they will also
> expose a couple serial ports too.  Which mode are you in to start with,
> and which mode are you switching too, and how are you doing that via
> sysfs?

Note that if this device is like the MC77xx, then it will switch control
protocol based on protocol snooping and *not* the selected USB
descriptors.  So if you probe it as MBIM then it becomes MBIM,
regardless of whether it is driven by cdc_mbim or qmi_wwan.  It does not
really support switching modes without being completely reset.  You
should let udev select a mode as soon as it is discovered and stick with
that.


BJørn