Problems with Sierra LTE MC7710 Device

[Harald Jung <support ecos de>]

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
/bin/usb-devices: line 79: printf: 0c: invalid number
I:  If#= 0 Alt= 0 #EPs= 1 Cls=02(commc) Sub=0e Prot=00 Driver=(none)
/bin/usb-devices: line 79: printf: 0d: invalid number
I:  If#= 0 Alt= 0 #EPs= 0 Cls=0a(data ) Sub=00 Prot=02 Driver=(none)

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)

dmesg output:

usb 1-1.5: new high-speed USB device number 7 using ehci_hcd
usb 1-1.5: config 1 has an invalid interface number: 8 but max is 3
usb 1-1.5: config 1 has no interface number 1
usb 1-1.5: config 2 has an invalid interface number: 12 but max is 1
usb 1-1.5: config 2 has an invalid interface number: 13 but max is 1
usb 1-1.5: config 2 has an invalid interface number: 13 but max is 1
usb 1-1.5: config 2 has no interface number 0
usb 1-1.5: config 2 has no interface number 1

As far as I understand are there 4 subdevices, as it should be normally.

00:14.0 USB controller: Intel Corporation 7 Series/C210 Series Chipset 
Family USB xHCI Host Controller (rev 04)

Maybe someone has seen something like this and knows a solution.

best regards

Harald