MC7304 connection?

[Bjørn Mork]

Aleksander Morgado <aleksander at aleksander.es> writes:

> Hey Bjørn,
>
> I see you pushed the kernel driver updates for the MC7304 (1199:68c0),
> so I'll assume you already tested one?

Nope.  Surprise - surprise, but I've actually tested very few of the
devices the driver claims to support :-)

Some are tested by others, but quite a few are added based only on
documentation sources like Windows *.inf files.  The theory is that we
can always fix up mistakes later if we get a negative report, and
negative reports are so much easier to get.  Getting positive reports
for all possible QMI devices is not likely to happen.  Most users won't
know that they should go look for a driver to add the device to.

This module device ID was added based on Sierra's "Driver Developers
Guide".

> This device shows up with 3 cdc-wdm/WWAN pairs. Of those, only two
> seem to work for me (the ones in ifs 8 and 10); while another one (the
> one in if 11) doesn't reply to any of my QMI commands. Any idea why is
> that? Are you sure it's a QMI interface?

Nope, not sure.  But it is listed as such in the Sierra docs.

The behaviour is interesting. It matches my experiences with the MC7710.
It also has a mode with 3 QMI functions, where the last one (if #20 on
the MC7710) does not work.  I tried to debug that, but it fails by just
not responding at all on the interrupt endpoint so there isn't really
that much to do.  It's disabled in the driver.

Sounds like we might have to do the same for the 68c0 device ID.

My theory so far has been that they mixed up endpoint addresses or
something in the firmware.  But it seems a little unlikely that a bug
like that would be carried over to the new 9x15 firmwares, especially
when they also change the USB descriptors using new interface numbers
for the 2 additional QMI functions.

> And the big issue now; I've tried to get the modem connected, but I
> don't seem to be able to do it. The QMI connection setup works well,
> but then dhclient will just timeout trying to get the IP setup. I've
> tried with using the IP settings that the modem reports in Get Current
> Settings, but even if I set the parameters I'm told to, nothing goes
> through the interface. Any idea what can be happening? Any hint on
> what I can do to debug this issue?

Hmm, this sounds vaguely familiar.  Wasn't there someone around here
with the exact same issues recently?  I don't remember how that went
anymore... But I can search for it.

> I'm running on a 3.14.4 kernel with qmi_wwan update with the new VID/PIDs.

That sounds fine.  There hasn't been much changes to the driver for a
long time, if we keep the cdc-wdm changes out of it.  And I guess we can
since QMI is working.


Bjørn