MC7750 libqmi

Dan Williams dcbw at
Mon Nov 4 21:55:06 CET 2013

On Mon, 2013-11-04 at 11:19 -0800, Tim Harvey wrote:
> Heath,
> I saw your thread here
> on the libqmi maillist archives and was wondering what the status is?
> I have a MC7750 that I've established a connection with using libqmi
> v1.6 but it seems after some time traffic stops being passed and
> 'qmi-network /dev/cdc-wdm0 status' shows disconnected. If I do a
> 'qmi-network /dev/cdc-wdm0 start' traffic resumes again.  It sounds
> like this is a different issue than you encountered?  I have the same
> results if I hack qmicli to add QMI_DEVICE_OPEN_FLAGS_NET_802_3 and
> QMI_DEVICE_OPEN_FLAGS_NET_NO_QOS_HEADER it seems to behave the same.
> Its possible that I don't have an adequate signal strength as I'm not
> clear yet how to determine with libqmi what radio band I'm connected
> with and what an appropriate signal level is.

I've got a 7750 that works fine here; how long is "after some time"?
I've used mine for at least a couple hours at a time, though only
stationary.  The LTE signal is almost always good (better than -70dbm)
which might be why it works so well :)

First, what firmware version?

qmicli -d /dev/cdc-wdm0 --dms-get-revision

To determine signal strength and other information, you want:

qmicli -d /dev/cdc-wdm0 --nas-get-signal-strength
qmicli -d /dev/cdc-wdm0 --nas-get-serving-system
qmicli -d /dev/cdc-wdm0 --nas-get-signal-info

Most likely you don't care what radio band you're using, you just care
what access technology (cdma, evdo, umts, lte) you're using and what the
signal strength is.


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