Re: Problems with Sierra LTE MC7710 Device

[Bjørn Mork <bjorn mork no>]

Harald Jung <support ecos de> writes:

> Hi,
>
> we have problems with a Sierra MC7710, it isn't even recognized by the
> kernel.
>
> The device should be included in the current kernel 3.6.11/3.7.2 and I
> think it is caused by an usb issue.
>
> When I take a look at the usb device, I see that there are only 2
> subdevices:
>
> T:  Bus=01 Lev=02 Prnt=02 Port=04 Cnt=03 Dev#=  7 Spd=480 MxCh= 0
> D:  Ver= 2.00 Cls=ef(misc ) Sub=02 Prot=01 MxPS=64 #Cfgs=  2
> P:  Vendor=1199 ProdID=68a2 Rev=00.06
> S:  Manufacturer=Sierra Wireless, Incorporated
> S:  Product=MC7710
> C:  #Ifs= 2 Cfg#= 2 Atr=e0 MxPwr=0mA

Hey!  I'd love to have that firmware!  Which version is this?  Right,
you probably have some problems getting that info without a driver.  But
that's fixable.

(I've asked my distributor for a newer firmware image, but haven't
gotten it yet)

> But it should look like this (found it in the net):
>
> T: Bus=01 Lev=02 Prnt=02 Port=04 Cnt=03 Dev#= 5 Spd=480 MxCh= 0
> D: Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
> P: Vendor=1199 ProdID=68a2 Rev=00.06
> S: Manufacturer=Sierra Wireless, Incorporated
> S: Product=MC7710
> C: #Ifs= 4 Cfg#= 1 Atr=e0 MxPwr=0mA
> I: If#= 0 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=ff Driver=(none)
> I: If#= 2 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=ff Driver=(none)
> I: If#= 3 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=ff Driver=(none)
> /usr/bin/usb-devices: line 79: printf: 08: invalid octal number
> I: If#= 0 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=ff Driver=(none)

Yes, that is what we've seen so far and what I've got. 

The card you have has MBIM firmware and is obviously in MBIM mode.  If
you are able to install a new kernel then please try 3.8-rc3 with
CONFIG_USB_NET_CDC_MBIM=m

I would very much like to know that goes.  It should work in theory,
creating wwanX and /dev/cdc-wdmY devices.  But do note that this
/dev/cdc-wdmY device is *not* speaking QMI.  It expects MBIM control
protocol messages.  Unfortunately there isn't any user app available for
that yet, but I believe Aleksander is just about to start coding a
libmbim.  And as usual I do have some hacky perl scripts if you want to
test things.

Based on experience with Sierra firmwares I am also pretty sure that it
is possible to switch this firmware into other modes, if you prefer to
use old style QMI applications.  But MBIM is the future :-)


Bjørn