Ease testing on /dev/cdc-wdmX where X > 0

[Dan Williams]

On Wed, 2012-04-11 at 12:48 +0200, Bjørn Mork wrote:
> Aleksander Morgado <aleksander at lanedo.com> writes:
> 
> >> bjorn at nemi:~$ ls -l /sys/class/net/wwan*
> >> lrwxrwxrwx 1 root root 0 Mar 27 09:16 /sys/class/net/wwan0 ->  ../../devices/pci0000:00/0000:00:1d.7/usb2/2-4/2-4:1.7/net/wwan0
> >> lrwxrwxrwx 1 root root 0 Mar 27 09:21 /sys/class/net/wwan1 ->  ../../devices/pci0000:00/0000:00:1d.7/usb2/2-1/2-1:1.4/net/wwan1
> >> lrwxrwxrwx 1 root root 0 Mar 27 09:22 /sys/class/net/wwan2 ->  ../../devices/pci0000:00/0000:00:1a.7/usb1/1-1/1-1:1.4/net/wwan2
> >> bjorn at nemi:~$ ls -l /sys/class/usb/cdc-wdm*
> >> lrwxrwxrwx 1 root root 0 Mar 27 09:17 /sys/class/usb/cdc-wdm0 ->  ../../devices/pci0000:00/0000:00:1d.7/usb2/2-4/2-4:1.5/usb/cdc-wdm0
> >> lrwxrwxrwx 1 root root 0 Mar 27 09:17 /sys/class/usb/cdc-wdm1 ->  ../../devices/pci0000:00/0000:00:1d.7/usb2/2-4/2-4:1.6/usb/cdc-wdm1
> >> lrwxrwxrwx 1 root root 0 Mar 27 09:21 /sys/class/usb/cdc-wdm2 ->  ../../devices/pci0000:00/0000:00:1d.7/usb2/2-1/2-1:1.3/usb/cdc-wdm2
> >> lrwxrwxrwx 1 root root 0 Mar 27 09:22 /sys/class/usb/cdc-wdm3 ->  ../../devices/pci0000:00/0000:00:1a.7/usb1/1-1/1-1:1.3/usb/cdc-wdm3
> >>
> >> Note that the mapping here is
> >>
> >> wwan0<=>  cdc-wdm0 _and_ cdc-wdm1
> >
> > Out of the topic of the original email, but... just wondering, are
> > those 2 cdm-wdm interfaces in that device fully equivalent, or do they
> > have different purposes?
> 
> I've never seen any differences in the functionality, but the USB
> interface string descriptors indicate different purposes:
> 
>  nemi:/tmp# grep . /sys/class/usb/cdc-wdm*/device/interface 
>  /sys/class/usb/cdc-wdm0/device/interface:Ericsson F3507g Mobile Broadband Minicard Device Management
>  /sys/class/usb/cdc-wdm1/device/interface:Ericsson F3507g Mobile Broadband Minicard PC SC Port
> 
> For the record: The same card exports 3 CDC ACM interfaces as well,
> where only the GPS one seems special:
> 
>  nemi:/tmp# grep . /sys/class/tty/ttyACM*/device/interface 
>  /sys/class/tty/ttyACM0/device/interface:Ericsson F3507g Mobile Broadband Minicard Modem
>  /sys/class/tty/ttyACM1/device/interface:Ericsson F3507g Mobile Broadband Minicard Data Modem
>  /sys/class/tty/ttyACM2/device/interface:Ericsson F3507g Mobile Broadband Minicard GPS Port
> 
> 
> So, given that you would normally use cdc_ether for networking, this
> card has 4 generic AT command interfaces available for monitoring, SMS,
> configuration etc. (excluding the GPS port which may be set up to output
> NMEA instead).

If you're running two APNs, one for your normal data connection and a
second one for MMS, then I believe you need to use PPP over a free AT
port to set up the second PDP context for MMS.  Kinda ugly, but hey, so
is MMS!

Dan