The MU609 modems from Huawei have a bug (confirmed by Huawei) that causes
the modem to reset if AT^GETPORTMODE is issued.
I have provided and example udev rule I use to disable this command as a
patch, feel free to drop that if its not acceptable. Since I cannot tell
the modem type from within the udev rules this is less specific than my
previous code based patch, but much simpler ;-)
I have two modems that share the same USB ID, however, neither supports the
^GETPORTMODE command (and one of them crashes when it is issued). Perhaps
someone with a Huawei that supports ^GETPORTMODE can check their USB ID's
and see if they clash.
Here is a comment from the Huawei devs:
> We confirmed this is a issue. This is Qualcomm baseband command at Data
> Card. We didn’t delete and block it. We will fix this issue in next FW.
> Thank you very much.
Sign-off-by: David McCullough <david.mccullough@accelecon.com>