FCC authentication with QMI over MBIM; try 1 -- Logs

Bjørn Mork bjorn at mork.no
Fri Jul 1 11:05:49 UTC 2016

Aleksander Morgado <aleksander at aleksander.es> writes:
> On Wed, Jun 29, 2016 at 6:11 PM, Bjørn Mork <bjorn at mork.no> wrote:
>> See
>> https://lists.freedesktop.org/archives/modemmanager-devel/2016-January/002595.html
>> I got so into the habit of separating the pin verify and connect
>> operations that forgot completely about that.  But the issue sounds
>> similar.  Maybe it is a timing issue of some sort, which applies on any
>> type of radio unlocking?
>> Can you repeat the issue if you send the FCC auth command manually
>> before enabling and connecting the modem?
> I don't think that made any difference, not sure.

Starting to think that it was just an arbitrary conincidence, and that
the real problem is that the MBIM session is just "flaky".

The good news is that I can reproduce the same problem on my MC7455 in
MBIM mode.  The bad news is that I am still unable to correlate the
problem to any specific input or configuration sequence. Sometimes the
session is just "stuck", like many of you have reported for the EM7455.
Connecting and all other MBIM management is fine.  But there is
absolutely nothing coming back from the modem over the bulk endpoint.

I tried resetting the modem and/or the USB link, and it ended up working
again after a few attempts.  But I got a feeling that is just by pure

There must be some trick making it more reliable. But what could it be?


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