Problem with mm-1.0.0 and Dell 5560

[Bjørn Mork]

Marek Kaluba <abulak at gmail.com> writes:

> # rmmod cdc_mbim
> # rmmod cdc_ncm
> # modprobe cdc_ncm prefer_mbim=N
> # mmcli -L
>
> Found 1 modems:
>         /org/freedesktop/ModemManager1/Modem/0 [Dell] DW5560
>
> # mmcli -m 0
>
> /org/freedesktop/ModemManager1/Modem/0 (device id 'f1f831063dbe34d741e5ea2723b18b70786ebd95')
>   -------------------------
>   Hardware |   manufacturer: 'Dell'
>            |          model: 'DW5560'
>            |       revision: 'R3C11'
>            |      supported: 'gsm-umts'
>            |        current: 'gsm-umts'
>            |   equipment id: '358994041358732'
>   -------------------------
>   System   |         device: '/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.6'
>            |        drivers: 'cdc_acm, cdc_mbim, cdc_wdm'


So the device is still bound to the cdc_mbim driver, meaning that the
modprobe cdc_ncm prefer_mbim=N had no effect and further testing of MM
without MBIM support is pointless.

I don't know why that didn't work.  Maybe we fail to reset the control
interface altsetting to 0?  I have assumed that the USB core did that
for us, but I must admit I never really verified it...

Could you dump the /sys/kernel/debug/usb/devices file after doing just

 # rmmod cdc_mbim
 # rmmod cdc_ncm

as well? If it shows altsetting #1 still active for if #6 then that
assumption is likely the problem here.

If not, then please verify that

  grep . /sys/module/cdc_ncm/parameters/prefer_mbim

shows 'N' and then "unplug" the modem and replug it if you can.  I
realize that this is an internal module, but there is usually a RF
switch you can use to do this.  Or you can use rfkill if there is a
driver supporting your laptop.

An alternative if you cannot "unplug" the modem would be creating a
/etc/modprobe.d/ncm.conf file with

  options cdc_ncm prefer_mbim=N

and reboot.

> I:  If#= 6 Alt= 0 #EPs= 1 Cls=02(comm.) Sub=0d Prot=00 Driver=cdc_mbim
> E:  Ad=86(I) Atr=03(Int.) MxPS=  32 Ivl=8ms
> I:* If#= 6 Alt= 1 #EPs= 1 Cls=02(comm.) Sub=0e Prot=00 Driver=cdc_mbim
> E:  Ad=86(I) Atr=03(Int.) MxPS=  32 Ivl=8ms

Thanks.  This shows that you do have both the NCM and MBIM alternatives
as expected, but that the MBIM altsetting is the active one.  Which it
wasn't supposed to be.


Bjørn