7455 modem not showing up in ifconfig

IoT Modules MC/EM Series
1

Hi, I have cross compiled both GobiNet and GobiSerial drivers for my ARM board, and I have integrated both drivers into my ARM kernel config. With this new kernel loaded onto my ARM board, I can see that both GobiNet and GobiSerial are properly loaded.

I am also able to cross compile and run the lite-connectmgrarm application program on my ARM board. I can start a LTE connection, AFAIK.

However when I do ifconfig on my ARM board, I do not see eth3 and eth4, which according to the dmesg log, GobiNet had registered.

I then did ifconfig eth3 up, and ifconfig eth4 up. But still I cannot get eth3 and eth4 to do anything.

Am I missing something obvious? Thanks for any tip!

usb 1-2.1: new high-speed USB device number 4 using bcm-ehci
usb 1-2.1: config 1 has an invalid interface number: 8 but max is 4
usb 1-2.1: config 1 has an invalid interface number: 10 but max is 4
usb 1-2.1: config 1 has no interface number 1
usb 1-2.1: config 1 has no interface number 4
usb 1-2.1: skipped 4 descriptors after interface
usb 1-2.1: skipped 4 descriptors after interface
usb 1-2.1: default language 0x0409
usb 1-2.1: udev 4, busnum 1, minor = 3
usb 1-2.1: New USB device found, idVendor=1199, idProduct=9071
usb 1-2.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 1-2.1: Product: Sierra Wireless MC7455 Qualcomm® Snapdragon™ X7 LTE-A
usb 1-2.1: Manufacturer: Sierra Wireless, Incorporated
usb 1-2.1: SerialNumber: LQ84327254021025
usb 1-2.1: usb_probe_device
usb 1-2.1: configuration #1 chosen from 1 choice
usb 1-2.1: adding 1-2.1:1.0 (config #1, interface 0)
GobiNet 1-2.1:1.0: usb_probe_interface
GobiNet 1-2.1:1.0: usb_probe_interface - got id
GobiSerial 1-2.1:1.0: usb_probe_interface
GobiSerial 1-2.1:1.0: usb_probe_interface - got id
GobiSerial 1-2.1:1.0: GobiSerial converter detected
usb 1-2.1: GobiSerial converter now attached to ttyUSB0
usb 1-2.1: adding 1-2.1:1.2 (config #1, interface 2)
GobiNet 1-2.1:1.2: usb_probe_interface
GobiNet 1-2.1:1.2: usb_probe_interface - got id
GobiSerial 1-2.1:1.2: usb_probe_interface
GobiSerial 1-2.1:1.2: usb_probe_interface - got id
GobiSerial 1-2.1:1.2: GobiSerial converter detected
usb 1-2.1: GobiSerial converter now attached to ttyUSB1
usb 1-2.1: adding 1-2.1:1.3 (config #1, interface 3)
GobiNet 1-2.1:1.3: usb_probe_interface
GobiNet 1-2.1:1.3: usb_probe_interface - got id
GobiSerial 1-2.1:1.3: usb_probe_interface
GobiSerial 1-2.1:1.3: usb_probe_interface - got id
GobiSerial 1-2.1:1.3: GobiSerial converter detected
usb 1-2.1: GobiSerial converter now attached to ttyUSB2
usb 1-2.1: adding 1-2.1:1.8 (config #1, interface 8)
GobiNet 1-2.1:1.8: usb_probe_interface
GobiNet 1-2.1:1.8: usb_probe_interface - got id
GobiNet 1-2.1:1.8: eth3: register ‘GobiNet’ at usb-bcm-ehci-2.1, GobiNet Ethernet Device, ce:60:b8:71:af:5a
USB Speed : USB 2.0
usb 1-2.1: adding 1-2.1:1.10 (config #1, interface 10)
GobiNet 1-2.1:1.10: usb_probe_interface
GobiNet 1-2.1:1.10: usb_probe_interface - got id
GobiNet 1-2.1:1.10: eth4: register ‘GobiNet’ at usb-bcm-ehci-2.1, GobiNet Ethernet Device, ce:60:b8:71:af:5a
USB Speed : USB 2.0
creating qcqmi0
RawIP mode
creating qcqmi1
RawIP mode

2

How about “ifconfig eth3 up” ?

3

Yes, I did that, and I see eth3 when I do ifconfig. But even after I run lite-connectionmgrarm to start a LTE connection, eth3 still has no IP address assigned to it. So I am not sure if eth3 is even real.

4

how about “dhclient eth3” or “udhcpc eth3”?
Not sure if you have the network manager, but you can also try to disable the network manager to retry.

5

Unfortuately I do not have either app in my busybox. But I think the basic question is why eth3 is not showing up in ifconfig.

Does anyone has prior experience in porting GobiNet and GobiSerial drivers into an embedded kernel tree? Do I need to change any other file under drivers/net/usb?

6

Actually I do have udhcpc. I ran udhcpc eth3 and it didnt do anything useful to eth3.

udhcpc eth3

udhcpc (v1.20.2) started
Sending discover…
Sending select for 172.19.100.150…
Lease of 172.19.100.150 obtained, lease time 86400
deleting routers
route: SIOCDELRT: No such process
adding dns 172.19.1.1
adding dns 172.19.1.2

route

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
default 172.19.0.1 0.0.0.0 UG 0 0 0 eth0
172.19.0.0 * 255.255.0.0 U 0 0 0 eth0

7

Didn’t you say " I see eth3 when I do ifconfig"?
For udhcpc, seems it can get ip address and dns address.

Have you tried to set the default network interface?
e.g.
route del default
route add default gw 172.19.100.150