Probing MBIM ports on devices with both MBIM and other cdc-wdmX devices

[Aleksander Morgado]

On 04/05/13 22:37, Bjørn Mork wrote:
> Probably more of a MM question, but this list needs som traffic :)
> 
> Just had a H5321gw user test MM with libmbim.  And one of the odd things
> happening was this (I've stripped out some lines inbetween here):
> 
>> <debug> [1367697017.475613] [mm-plugin.c:772] mm_plugin_supports_port(): (Ericsson MBM) [cdc-wdm0] probe required: 'mbim'
>> <debug> [1367697017.482773] [mm-port-probe.c:1331] mm_port_probe_run(): (usbmisc/cdc-wdm0) launching port probing: 'mbim'
>> <debug> [1367697018.137668] [mm-plugin.c:772] mm_plugin_supports_port(): (Ericsson MBM) [cdc-wdm2] probe required: 'mbim'
>> <debug> [1367697018.176998] [mm-port-probe.c:1331] mm_port_probe_run(): (usbmisc/cdc-wdm2) launching port probing: 'mbim'
>> <debug> [1367697018.407780] [mm-plugin.c:772] mm_plugin_supports_port(): (Ericsson MBM) [cdc-wdm1] probe required: 'mbim'
>> <debug> [1367697018.427487] [mm-port-probe.c:1331] mm_port_probe_run(): (usbmisc/cdc-wdm1) launching port probing: 'mbim'
>> <debug> [1367697018.618970] [mm-port-probe.c:317] mm_port_probe_set_result_mbim(): (usbmisc/cdc-wdm0) port is not MBIM-capable
>> <debug> [1367697018.623238] [mm-port-probe.c:317] mm_port_probe_set_result_mbim(): (usbmisc/cdc-wdm2) port is not MBIM-capable
>> <debug> [1367697018.627512] [mm-port-probe.c:317] mm_port_probe_set_result_mbim(): (usbmisc/cdc-wdm1) port is not MBIM-capable
> 
> I did not expect the two AT command cdc-wdmX ports to be MBIM
> probed. But looking again at the probe filter, I see that it is per
> device and not per port:
> http://cgit.freedesktop.org/ModemManager/ModemManager/commit/?id=6b379e525dbcc117a82fb367a6db2146042880ab
> 
> I guess that's necessary to support Huawei QMI modems using the 3.4 and
> 3.5 drivers.   But it doesn't look good.  Why not launch an AT probe on
> all ports as well?  It would have succeeded for two of the ports
> above... 
> 

By default cdc-wdm ports are never probed for AT capabilities in MM,
only ttys are assumed to be either AT or QCDM. We could have a new more
generic MMPortAt in addition to the MMPortAtSerial I guess. Question is,
are these ports usually only in Ericsson devices? Or is it really more
generic, like any cdc-wdm port found in modems out there may very well
be an ÄT port?

-- 
Aleksander