Unable to connect to ATT after kernel update

After kernel update I am unable to connect to cellular network.

I have installed autoconnect/reconnect service and follow the QMI setup docs.

When I get to the quectel-CM step then connection manger fails to finish and does not connect:

pi@pi2cam:~/files/quectel-CM $ sudo ./quectel-CM -s
[12-04_19:15:26:107] Quectel_QConnectManager_Linux_V1.6.0.12
[12-04_19:15:26:109] Find /sys/bus/usb/devices/1-1.2 idVendor=0x2c7c idProduct=0x125, bus=0x001, dev=0x004
[12-04_19:15:26:109] Auto find qmichannel = /dev/cdc-wdm0
[12-04_19:15:26:109] Auto find usbnet_adapter = wwan0
[12-04_19:15:26:110] netcard driver = qmi_wwan, driver version = 22-Aug-2005
[12-04_19:15:26:110] ioctl(0x89f3, qmap_settings) failed: Operation not supported, rc=-1
[12-04_19:15:26:110] Modem works in QMI mode
[12-04_19:15:26:138] cdc_wdm_fd = 7
[12-04_19:15:26:240] Get clientWDS = 19
[12-04_19:15:26:274] Get clientDMS = 1
[12-04_19:15:26:308] Get clientNAS = 3
[12-04_19:15:26:343] Get clientUIM = 1
[12-04_19:15:26:378] Get clientWDA = 1
[12-04_19:15:26:411] requestBaseBandVersion EC25AFAR05A04M4G
[12-04_19:15:26:547] requestGetSIMStatus SIMStatus: SIM_READY
[12-04_19:15:26:547] requestSetProfile[1] ///0
[12-04_19:15:26:615] requestGetProfile[1] ///0
[12-04_19:15:26:649] requestRegistrationState2 MCC: 310, MNC: 410, PS: Attached, DataCap: LTE
[12-04_19:15:26:684] requestQueryDataCall IPv4ConnectionStatus: DISCONNECTED
[12-04_19:15:26:684] ifconfig wwan0 down
[12-04_19:15:26:701] ifconfig wwan0
[12-04_19:15:26:749] requestSetupDataCall WdsConnectionIPv4Handle: 0x872154f0
[12-04_19:15:26:853] change mtu 1500 -> 1430
[12-04_19:15:26:854] ifconfig wwan0 up
[12-04_19:15:26:866] busybox udhcpc -f -n -q -t 5 -i wwan0
udhcpc: started, v1.30.1
No resolv.conf for interface wwan0.udhcpc
udhcpc: sending discover
udhcpc: sending discover
udhcpc: sending discover
udhcpc: sending discover
udhcpc: sending discover
udhcpc: no lease, failing

as per hanleynh1 (Error connecting to QMI No resolv.conf for interface wwan0.udhcpc, no lease failing) adding “denyinterfaces wwan0” to /etc/dhcpcd.conf fixed the issue for me

The one thing I do not understand is the /usr/src/qmi_reconnect.sh executes quectel-CM but the connection manager never returns control to the calling program so I am not sure the reconnect script really works. It will only check “ping” if quectel-CM fails. And if is fails the connection is lost so no need to test with ping.

I assume we need 2 services, one to run the connection manager and another to check (ping) and if check fails cycle the first service.

I am not sure how to test this – let me know if I am wrong or if you have ideas how to test it.


Steps to test the connection are available in Section 4.3 of the Linux Driver Guide.

on a new build getting this:

Checking Kernel
Driver for 5.10.5-v7l+ kernel not found

Any idea when this kernel version will be supported?


Hi @williamkeeling,

The kernel already supports this but there was an error in the QMI installer file, it is now resolved.

Please try to build again.