Sierra EM7455 not recognized

Aleksander Morgado aleksander at
Mon Jun 27 05:47:49 UTC 2016

On Sun, Jun 26, 2016 at 9:01 PM, Samo Ratnik <samo.ratnik at> wrote:
> Some good news and some bad news. The good news is that I got the thing
> working. I'm using Arch's "stock" NetworkManager and ModemManager and the
> AUR packages mentioned above. I simply issue the "sudo qmicli
> --device-open-mbim -d /dev/cdc-wdm0 --dms-set-fcc-authentication" command
> and then restart the ModemManager with NetworkManager running all the time.
> I disabled wifi and bluetooth in the NetworkManager (don't know if this is
> relevant in any way) and created a "Mobile Broadband" configuration for my
> mobile operator which I open.
> The bad news is that the thing is *very* flaky. When issuing the "qmicli
> --device-open-mbim ..." I often get various errors. The ones that I got are
> enumerated here:

I fixed one of those issues in libqmi's qmi-over-mbim branch. Still,
you're running MBIM commands at the same time as ModemManager, and
you're not using the proxy option. For all the qmicli/mbimcli commands
you manually run, please use the "-p" option if ModemManager is also

> And even when that works okay I have to restart the ModemManager *a lot* to
> get a working ping. Sometimes I even shutdown the computer when I do more
> than 10 ModemManager restarts. Here's a journalctl output of a session where
> I had to issue the qmicli command twice and then the ModemManager restart
> worked in the first try:

I believe the MM restarts you require here are because you're not
using the proxy option in qmicli; and responses from the modem aren't
going where they should.


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