Losing USB ethernet connection

When I reboot my mangOH yellow I am able to briefly see 192.168.2.2 however after about 15secs it disappears.

My dev machine is Ubuntu 18.04, if i watch the network connections I can see it switch from “Usb Ethernet” to “Mobile Broadband”, when it switches to the later is when I lose connection to the device.

Running configECM off/on results in the same behavior, i can ping the board for a brief moment and eventually stops.

root@swi-mdm9x28-wp:~# configEcm off
DONE
root@swi-mdm9x28-wp:~# configEcm on

No target address. Using defaults.
[  619.021328] ch_notify on a closed smd_pkt_dev id:2
[  619.026233] BUG: sleeping function called from invalid context at /usr/src/kernel/kernel/locking/mutex.c:97
[  619.035138] in_atomic(): 1, irqs_disabled(): 0, pid: 3398, name: usb
[  619.041342] Preemption disabled at:[<  (null)>]   (null)
[  619.066970] [RMNET:HI] rmnet_config_notify_cb(): Kernel is trying to unregister ecm0
[  619.120381] [RMNET:HI] rmnet_config_notify_cb(): Kernel is trying to unregister ecm0
umount: can't unmount /dev/usb-ffs/adb: No such file or directory
DONE
root@swi-mdm9x28-wp:~# [  630.923779] diag: In diag_process_hdlc_pkt, bad CRC. Dropping packet

dmesg from my dev machine

french@ubuntu18Dev:~/Downloads$ dmesg | tail
[  770.400504] usb 3-4: Qualcomm USB modem converter now attached to ttyUSB1
[  770.431320] qcserial 3-4:1.2: Qualcomm USB modem converter detected
[  770.431383] usb 3-4: Qualcomm USB modem converter now attached to ttyUSB2
[  770.463320] qcserial 3-4:1.3: Qualcomm USB modem converter detected
[  770.463378] usb 3-4: Qualcomm USB modem converter now attached to ttyUSB3
[  770.495354] qmi_wwan 3-4:1.8: cdc-wdm1: USB WDM device
[  770.496472] qmi_wwan 3-4:1.8 wwan0: register 'qmi_wwan' at usb-0000:08:00.1-4, WWAN/QMI device, 82:03:01:c8:dd:8d
[  770.502422] cdc_ether 3-4:1.19 usb0: register 'cdc_ether' at usb-0000:08:00.1-4, CDC Ethernet Device, 1e:f9:72:b3:ae:63
[  770.531662] cdc_ether 3-4:1.19 enp8s0f1u4i19: renamed from usb0
[  770.564350] qmi_wwan 3-4:1.8 wwp8s0f1u4i8: renamed from wwan0

ifconfig from mangOH

root@swi-mdm9x28-wp:~# ifconfig
bridge0   Link encap:Ethernet  HWaddr AA:67:EE:27:3E:3E  
          inet addr:192.168.225.1  Bcast:192.168.225.255  Mask:255.255.255.0
          inet6 addr: fe80::a867:eeff:fe24:3b3b/64 Scope:Link
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:0 (0.0 B)  TX bytes:76 (76.0 B)

ecm0      Link encap:Ethernet  HWaddr 6A:C9:30:6B:C3:E1  
          inet addr:192.168.2.2  Bcast:192.168.2.255  Mask:255.255.255.0
          inet6 addr: fe80::68c9:30ff:fe6b:c3e1/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:35 errors:0 dropped:0 overruns:0 frame:0
          TX packets:10 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:4100 (4.0 KiB)  TX bytes:984 (984.0 B)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:2 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:152 (152.0 B)  TX bytes:152 (152.0 B)

rmnet0    Link encap:UNSPEC  HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  
          UP RUNNING  MTU:2000  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

ip a from dev machine

french@ubuntu18Dev:~/Downloads$ ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: enp7s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc fq_codel state DOWN group default qlen 1000
    link/ether 24:4b:fe:57:a0:91 brd ff:ff:ff:ff:ff:ff
3: wlp6s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 0c:7a:15:ef:23:dd brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.8/24 brd 192.168.0.255 scope global dynamic noprefixroute wlp6s0
       valid_lft 85092sec preferred_lft 85092sec
    inet6 fe80::b8fc:b53b:b112:e53f/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
10: wwp8s0f1u4i8: <POINTOPOINT,MULTICAST,NOARP> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/none 
11: enp8s0f1u4i19: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 1e:f9:72:b3:ae:63 brd ff:ff:ff:ff:ff:ff

Currently i have a fresh install of R13 and a clean user1 partition.

Seems there is no ip address for enp8s0f1u4i19 which was the usb ecm interface.

You can set it up manually in pc by:

sudo ifconfig enp8s0f1u4i19 192.168.2.3

Also you might need to shut down firewall on module by:

iptables -I INPUT -j ACCEPT

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Thanks @jyijyi,

Looking deeper in the forums I see some people have had a similar issue when working on ubuntu machines (non VM).

that is why i suggest you manually set the IP address.

Remove modemmanager from Ubuntu:

 sudo apt remove modemmanager
1 Like