Re: Alcatel X200 troubleshooting

[Dan Williams <dcbw redhat com>]

On Mon, 2011-04-18 at 14:04 +0200, Javier Almasoft wrote:
> I just spent a day chasing a troublesome adapter supplied by a local
> carrier (Euskaltel in Spain), identified by usb ID 1bbb:f000, and
> after the usb_modeswitch trick, by 1bbb:0017. This is identified by
> another people as an Alcatel X200 series. It was not recognized by
> Network Manager most of the times, throwing the following message on
> syslog:
> 
> hp NetworkManager: <WARN>  user_list_connections_cb(): Couldn't
> retrieve connections: Did not receive a reply. Possible causes
> include: the remote application did not send a reply, the message bus
> security policy blocked the reply, the reply timeout expired, or the
> network connection was broken..
> 
> By activating debug mode in modem manager, my conclusion was that too
> much time was wasted by testing the six! serial ports this device was
> opening, for GSM capabilities (only the fourth and sixth were
> capable). So, the solution seemed to be to ignore the first four ports
> when testing this particular device.
> Looking at mailing lists, I thought the solution was to write a udev
> rule assigning the value ID_MM_DEVICE_IGNORE to skip the non
> GSM-capable ports, but apparently this value is only to ignore entire
> devices, not individual ports.
> 
> Then I grabbed the source (ModemManager-0.4) and looked for a way to
> do this, but none was obvious for me. So I made a few changes to the
> source (patch attached) to include awareness of a new value,
> ID_MM_PORT_IGNORE. The changes were done only to the longcheer and
> generic plugins (those were the ones activated in this case). With
> this, and the proper udev rule (also included in the patch)
> recognition by Network Manager is almost instantaneous and flawless.
> 
> Please tell me is there is another way to do this or if my solution is
> of interest to anyone.

Normally we don't want to blacklist specific ports as sometimes
manufacturers (like Huawei and others) use the same USB ID for multiple
devices and the ports used on those might be different.  For other
devices (Sierra, Novatel, etc) AT commands can be used to change port
assignments around and thus you really don't know which port is the
secondary AT port and which is the GPS port based on hardcoded numbers.

But in this case, if you're sure neither of these apply, we could
potentially blacklist those ports.  The only way of doing this is to use
the USB interface # since that stays constant, while port device names
(ie ttyUSBx or ttyACMx) do not.

Some devices already do this, like the x22x driver.  Any port that's not
explicitly tagged with ID_MM_X22X_TAGGED gets ignored.

Dan