Netgear 340u

[Bjørn Mork]

Ramesh Siripurapu <ramesh.siripurapu at aptiwiz.com> writes:

> After banging my head for a day, figured that cdc-mbim is the
> culprit. Once I remove that module, then everything is good. I guess
> that module binding to modem when it was in MBIM mode and then
> switching to QMI, unbinding cdc-mbim and qmi_wwan binding is causing
> firmware go bonkers. It isn't sending out any Bo packets although
> usbmon shows it is sending out Bo packets.

I wish this surprised me, but it doesn't.

The multiconfiguration support in these firmwares assume that the
OS/driver selects the wanted configuration *before* they start
communicating with the selected functions.  The cdc_mbim driver will
exchange a bit of config info when it probes an MBIM function.  So if
the configuration switch happens after cdc_mbim has started probing,
then the firmware might not recover properly.

When you say "usbmon shows it is sending out Bo packets", would that by
any chance be a stream of empty (zero length) packets?  I've see that
from the MC7710 when doing "late" config switching.


Bjørn