i am new on kernel development, i can successfully use my Huawei vodafone k4203 usb modem with kernel version 4.15(I test it on ubuntu-18.04.1 LTS with kernel 4.15 (i donwlaod this iso on 2018)) but when i try to use it with the newer 5.x.x kernel i get the error "kernel: cdc_mbim 2-1.5:2.0: SET_NTB_FORMAT failed kernel: cdc_mbim 2-1.5:2.0: bind() failure" when I want to use I enter on ubuntu-18.04.1LTS, insert the device and reboot and enter on fedora-36 but when I enter the fedora-36 and insert the device, reboot and enter the ubuntu-18.04.1 LTS, the device fails on ubuntu-18.04.1 LTS, just remove and insert again and it works Now i'm use (Fedora_36 kernel 5.18.13-200.x86_64) I compiled the kernel-{5.4,4.19} longterm and the problem persist But when I access the 4.x.x kernel then reboot the PC and access the 5.x.x kernel it works, do you have any idea how I can solve this problem ? :) Note: the modem has a dhcp server and web server. My log on fedora-36: [ 115.571291] usb 2-1.4: new high-speed USB device number 7 using ehci-pci [ 115.652037] usb 2-1.4: New USB device found, idVendor=12d1, idProduct=1f1c, bcdDevice= 1.02 [ 115.652045] usb 2-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ 115.652049] usb 2-1.4: Product: HUAWEI Mobile [ 115.652052] usb 2-1.4: Manufacturer: Vodafone(Huawei) [ 115.652054] usb 2-1.4: SerialNumber: FFFFFFFFFFFFFFFF [ 115.779381] usb-storage 2-1.4:1.0: USB Mass Storage device detected [ 115.779821] scsi host4: usb-storage 2-1.4:1.0 [ 115.779917] usbcore: registered new interface driver usb-storage [ 115.787770] usbcore: registered new interface driver uas [ 116.646327] usbcore: registered new interface driver cdc_ether [ 116.655897] usbcore: registered new interface driver cdc_ncm [ 116.665733] usbcore: registered new interface driver cdc_wdm [ 116.706710] cdc_mbim 2-1.4:2.0: SET_NTB_FORMAT failed [ 116.730917] cdc_mbim 2-1.4:2.0: bind() failure [ 116.730987] usbcore: registered new interface driver cdc_mbim [ 116.935660] usb 2-1.4: USB disconnect, device number 7 [ 121.459317] usb 2-1.4: new high-speed USB device number 8 using ehci-pci [ 121.539511] usb 2-1.4: New USB device found, idVendor=12d1, idProduct=1f1c, bcdDevice= 1.02 [ 121.539520] usb 2-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ 121.539525] usb 2-1.4: Product: HUAWEI Mobile [ 121.539528] usb 2-1.4: Manufacturer: Vodafone(Huawei) [ 121.539531] usb 2-1.4: SerialNumber: FFFFFFFFFFFFFFFF [ 121.594546] usb-storage 2-1.4:1.0: USB Mass Storage device detected [ 121.594911] scsi host4: usb-storage 2-1.4:1.0 [ 122.466808] cdc_mbim 2-1.4:2.0: SET_NTB_FORMAT failed [ 122.490514] cdc_mbim 2-1.4:2.0: bind() failure [ 122.567541] usb 2-1.4: USB disconnect, device number 8 [ 127.091345] usb 2-1.4: new high-speed USB device number 9 using ehci-pci [ 127.172930] usb 2-1.4: New USB device found, idVendor=12d1, idProduct=1f1c, bcdDevice= 1.02 [ 127.172939] usb 2-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ 127.172943] usb 2-1.4: Product: HUAWEI Mobile [ 127.172947] usb 2-1.4: Manufacturer: Vodafone(Huawei) [ 127.172949] usb 2-1.4: SerialNumber: FFFFFFFFFFFFFFFF [ 127.226234] usb-storage 2-1.4:1.0: USB Mass Storage device detected [ 127.226706] scsi host4: usb-storage 2-1.4:1.0 [ 128.090497] cdc_mbim 2-1.4:2.0: SET_NTB_FORMAT failed [ 128.114422] cdc_mbim 2-1.4:2.0: bind() failure [ 128.199565] usb 2-1.4: USB disconnect, device number 9 /var/lib/messages: Aug 7 17:59:49 localhost kernel: usb 2-1.4: Product: HUAWEI Mobile Aug 7 17:59:49 localhost kernel: usb 2-1.4: Manufacturer: Vodafone(Huawei) Aug 7 17:59:49 localhost kernel: usb 2-1.4: SerialNumber: FFFFFFFFFFFFFFFF Aug 7 17:59:49 localhost mtp-probe[1531]: checking bus 2, device 7: "/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4" Aug 7 17:59:49 localhost mtp-probe[1531]: bus: 2, device: 7 was not an MTP device Aug 7 17:59:49 localhost systemd[1]: Created slice system-usb_modeswitch.slice - Slice /system/usb_modeswitch. Aug 7 17:59:49 localhost systemd[1]: Starting usb_modeswitch@2-1.4:1.0.service - USB_ModeSwitch_2-1.4:1.0... Aug 7 17:59:49 localhost kernel: usb-storage 2-1.4:1.0: USB Mass Storage device detected Aug 7 17:59:49 localhost kernel: scsi host4: usb-storage 2-1.4:1.0 Aug 7 17:59:49 localhost kernel: usbcore: registered new interface driver usb-storage Aug 7 17:59:49 localhost kernel: usbcore: registered new interface driver uas Aug 7 17:59:49 localhost mtp-probe[1546]: checking bus 2, device 7: "/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4" Aug 7 17:59:49 localhost mtp-probe[1546]: bus: 2, device: 7 was not an MTP device Aug 7 17:59:50 localhost usb_modeswitch[1551]: switch device 12d1:1f1c on 002/007 Aug 7 17:59:50 localhost kernel: usbcore: registered new interface driver cdc_ether Aug 7 17:59:50 localhost kernel: usbcore: registered new interface driver cdc_ncm Aug 7 17:59:50 localhost kernel: usbcore: registered new interface driver cdc_wdm Aug 7 17:59:50 localhost kernel: cdc_mbim 2-1.4:2.0: SET_NTB_FORMAT failed Aug 7 17:59:50 localhost kernel: cdc_mbim 2-1.4:2.0: bind() failure Aug 7 17:59:50 localhost kernel: usbcore: registered new interface driver cdc_mbim Aug 7 17:59:50 localhost kernel: usb 2-1.4: USB disconnect, device number 7 Aug 7 17:59:55 localhost kernel: usb 2-1.4: new high-speed USB device number 8 using ehci-pci Aug 7 17:59:55 localhost kernel: usb 2-1.4: New USB device found, idVendor=12d1, idProduct=1f1c, bcdDevice= 1.02 Aug 7 17:59:55 localhost kernel: usb 2-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3 Aug 7 17:59:55 localhost kernel: usb 2-1.4: Product: HUAWEI Mobile Aug 7 17:59:55 localhost kernel: usb 2-1.4: Manufacturer: Vodafone(Huawei) Aug 7 17:59:55 localhost kernel: usb 2-1.4: SerialNumber: FFFFFFFFFFFFFFFF Aug 7 17:59:55 localhost kernel: usb-storage 2-1.4:1.0: USB Mass Storage device detected Aug 7 17:59:55 localhost kernel: scsi host4: usb-storage 2-1.4:1.0 Aug 7 17:59:55 localhost mtp-probe[1565]: checking bus 2, device 8: "/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4" Aug 7 17:59:55 localhost mtp-probe[1565]: bus: 2, device: 8 was not an MTP device Aug 7 17:59:55 localhost systemd[1]: usb_modeswitch@2-1.4:1.0.service: Main process exited, code=killed, status=15/TERM Aug 7 17:59:55 localhost systemd[1]: usb_modeswitch@2-1.4:1.0.service: Failed with result 'signal'. Aug 7 17:59:55 localhost systemd[1]: Stopped usb_modeswitch@2-1.4:1.0.service - USB_ModeSwitch_2-1.4:1.0. Aug 7 17:59:55 localhost audit[1]: SERVICE_START pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 msg='unit=usb_modeswitch@2-1.4:1.0 comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=failed' Aug 7 17:59:55 localhost systemd[1]: Starting usb_modeswitch@2-1.4:1.0.service - USB_ModeSwitch_2-1.4:1.0... Aug 7 17:59:55 localhost mtp-probe[1575]: checking bus 2, device 8: "/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4" Aug 7 17:59:55 localhost mtp-probe[1575]: bus: 2, device: 8 was not an MTP device Aug 7 17:59:55 localhost usb_modeswitch[1579]: switch device 12d1:1f1c on 002/008 Aug 7 17:59:56 localhost kernel: cdc_mbim 2-1.4:2.0: SET_NTB_FORMAT failed Aug 7 17:59:56 localhost kernel: cdc_mbim 2-1.4:2.0: bind() failure Aug 7 17:59:56 localhost kernel: usb 2-1.4: USB disconnect, device number 8 Aug 7 18:00:00 localhost kernel: usb 2-1.4: new high-speed USB device number 9 using ehci-pci Aug 7 18:00:00 localhost kernel: usb 2-1.4: New USB device found, idVendor=12d1, idProduct=1f1c, bcdDevice= 1.02 Aug 7 18:00:00 localhost kernel: usb 2-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3 Aug 7 18:00:00 localhost kernel: usb 2-1.4: Product: HUAWEI Mobile Aug 7 18:00:00 localhost kernel: usb 2-1.4: Manufacturer: Vodafone(Huawei) Aug 7 18:00:00 localhost kernel: usb 2-1.4: SerialNumber: FFFFFFFFFFFFFFFF Aug 7 18:00:01 localhost kernel: usb-storage 2-1.4:1.0: USB Mass Storage device detected Aug 7 18:00:01 localhost kernel: scsi host4: usb-storage 2-1.4:1.0 Aug 7 18:00:01 localhost mtp-probe[1586]: checking bus 2, device 9: "/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4" Aug 7 18:00:01 localhost mtp-probe[1586]: bus: 2, device: 9 was not an MTP device Aug 7 18:00:01 localhost systemd[1]: usb_modeswitch@2-1.4:1.0.service: Main process exited, code=killed, status=15/TERM Aug 7 18:00:01 localhost systemd[1]: usb_modeswitch@2-1.4:1.0.service: Failed with result 'signal'. Aug 7 18:00:01 localhost systemd[1]: Stopped usb_modeswitch@2-1.4:1.0.service - USB_ModeSwitch_2-1.4:1.0. Aug 7 18:00:01 localhost audit[1]: SERVICE_START pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 msg='unit=usb_modeswitch@2-1.4:1.0 comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=failed' Aug 7 18:00:01 localhost mtp-probe[1594]: checking bus 2, device 9: "/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4" Aug 7 18:00:01 localhost systemd[1]: Starting usb_modeswitch@2-1.4:1.0.service - USB_ModeSwitch_2-1.4:1.0... Aug 7 18:00:01 localhost mtp-probe[1594]: bus: 2, device: 9 was not an MTP device Aug 7 18:00:01 localhost usb_modeswitch[1601]: switch device 12d1:1f1c on 002/009 Aug 7 18:00:01 localhost kernel: cdc_mbim 2-1.4:2.0: SET_NTB_FORMAT failed Aug 7 18:00:01 localhost kernel: cdc_mbim 2-1.4:2.0: bind() failure Aug 7 18:00:01 localhost kernel: usb 2-1.4: USB disconnect, device number 9 Aug 7 18:00:06 localhost kernel: usb 2-1.4: new high-speed USB device number 10 using ehci-pci Aug 7 18:00:06 localhost kernel: usb 2-1.4: New USB device found, idVendor=12d1, idProduct=1f1c, bcdDevice= 1.02 Aug 7 18:00:06 localhost kernel: usb 2-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3 Aug 7 18:00:06 localhost kernel: usb 2-1.4: Product: HUAWEI Mobile Aug 7 18:00:06 localhost kernel: usb 2-1.4: Manufacturer: Vodafone(Huawei) Aug 7 18:00:06 localhost kernel: usb 2-1.4: SerialNumber: FFFFFFFFFFFFFFFF Aug 7 18:00:06 localhost kernel: usb-storage 2-1.4:1.0: USB Mass Storage device detected Aug 7 18:00:06 localhost kernel: scsi host4: usb-storage 2-1.4:1.0 Aug 7 18:00:06 localhost mtp-probe[1611]: checking bus 2, device 10: "/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4" Aug 7 18:00:06 localhost mtp-probe[1611]: bus: 2, device: 10 was not an MTP device Aug 7 18:00:06 localhost systemd[1]: usb_modeswitch@2-1.4:1.0.service: Main process exited, code=killed, status=15/TERM Aug 7 18:00:06 localhost systemd[1]: usb_modeswitch@2-1.4:1.0.service: Failed with result 'signal'. Aug 7 18:00:06 localhost systemd[1]: Stopped usb_modeswitch@2-1.4:1.0.service - USB_ModeSwitch_2-1.4:1.0. Aug 7 18:00:06 localhost audit[1]: SERVICE_START pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 msg='unit=usb_modeswitch@2-1.4:1.0 comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=failed' Aug 7 18:00:06 localhost systemd[1]: Starting usb_modeswitch@2-1.4:1.0.service - USB_ModeSwitch_2-1.4:1.0... Aug 7 18:00:06 localhost mtp-probe[1620]: checking bus 2, device 10: "/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4" Aug 7 18:00:06 localhost mtp-probe[1620]: bus: 2, device: 10 was not an MTP device Aug 7 18:00:07 localhost usb_modeswitch[1625]: switch device 12d1:1f1c on 002/010 Aug 7 18:00:07 localhost kernel: cdc_mbim 2-1.4:2.0: SET_NTB_FORMAT failed Aug 7 18:00:07 localhost kernel: cdc_mbim 2-1.4:2.0: bind() failure Aug 7 18:00:07 localhost kernel: usb 2-1.4: USB disconnect, device number 10 Aug 7 18:00:12 localhost kernel: usb 2-1.4: new high-speed USB device number 11 using ehci-pci Aug 7 18:00:12 localhost kernel: usb 2-1.4: New USB device found, idVendor=12d1, idProduct=1f1c, bcdDevice= 1.02 Aug 7 18:00:12 localhost kernel: usb 2-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3 Aug 7 18:00:12 localhost kernel: usb 2-1.4: Product: HUAWEI Mobile Aug 7 18:00:12 localhost kernel: usb 2-1.4: Manufacturer: Vodafone(Huawei) Aug 7 18:00:12 localhost kernel: usb 2-1.4: SerialNumber: FFFFFFFFFFFFFFFF Aug 7 18:00:12 localhost kernel: usb-storage 2-1.4:1.0: USB Mass Storage device detected Aug 7 18:00:12 localhost kernel: scsi host4: usb-storage 2-1.4:1.0 Aug 7 18:00:12 localhost mtp-probe[1633]: checking bus 2, device 11: "/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4" Aug 7 18:00:12 localhost mtp-probe[1633]: bus: 2, device: 11 was not an MTP device Aug 7 18:00:12 localhost systemd[1]: usb_modeswitch@2-1.4:1.0.service: Main process exited, code=killed, status=15/TERM Aug 7 18:00:12 localhost systemd[1]: usb_modeswitch@2-1.4:1.0.service: Failed with result 'signal'. Aug 7 18:00:12 localhost systemd[1]: Stopped usb_modeswitch@2-1.4:1.0.service - USB_ModeSwitch_2-1.4:1.0. Aug 7 18:00:12 localhost audit[1]: SERVICE_START pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 msg='unit=usb_modeswitch@2-1.4:1.0 comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=failed' Aug 7 18:00:12 localhost systemd[1]: Starting usb_modeswitch@2-1.4:1.0.service - USB_ModeSwitch_2-1.4:1.0... Aug 7 18:00:12 localhost mtp-probe[1643]: checking bus 2, device 11: "/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4" Aug 7 18:00:12 localhost mtp-probe[1643]: bus: 2, device: 11 was not an MTP device Aug 7 18:00:12 localhost usb_modeswitch[1647]: switch device 12d1:1f1c on 002/011 Aug 7 18:00:13 localhost kernel: cdc_mbim 2-1.4:2.0: SET_NTB_FORMAT failed Aug 7 18:00:13 localhost kernel: cdc_mbim 2-1.4:2.0: bind() failure Aug 7 18:00:13 localhost kernel: usb 2-1.4: USB disconnect, device number 11 Aug 7 18:00:17 localhost kernel: usb 2-1.4: new high-speed USB device number 12 using ehci-pci Aug 7 18:00:17 localhost kernel: usb 2-1.4: New USB device found, idVendor=12d1, idProduct=1f1c, bcdDevice= 1.02 Aug 7 18:00:17 localhost kernel: usb 2-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3 Aug 7 18:00:17 localhost kernel: usb 2-1.4: Product: HUAWEI Mobile Aug 7 18:00:17 localhost kernel: usb 2-1.4: Manufacturer: Vodafone(Huawei) Aug 7 18:00:17 localhost kernel: usb 2-1.4: SerialNumber: FFFFFFFFFFFFFFFF Aug 7 18:00:17 localhost kernel: usb-storage 2-1.4:1.0: USB Mass Storage device detected Aug 7 18:00:17 localhost kernel: scsi host4: usb-storage 2-1.4:1.0 Aug 7 18:00:17 localhost mtp-probe[1654]: checking bus 2, device 12: "/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4" Aug 7 18:00:17 localhost mtp-probe[1654]: bus: 2, device: 12 was not an MTP device Aug 7 18:00:17 localhost systemd[1]: usb_modeswitch@2-1.4:1.0.service: Main process exited, code=killed, status=15/TERM Aug 7 18:00:17 localhost systemd[1]: usb_modeswitch@2-1.4:1.0.service: Failed with result 'signal'. Aug 7 18:00:17 localhost systemd[1]: Stopped usb_modeswitch@2-1.4:1.0.service - USB_ModeSwitch_2-1.4:1.0. Aug 7 18:00:17 localhost audit[1]: SERVICE_START pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 msg='unit=usb_modeswitch@2-1.4:1.0 comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=failed' Aug 7 18:00:17 localhost systemd[1]: Starting usb_modeswitch@2-1.4:1.0.service - USB_ModeSwitch_2-1.4:1.0... Aug 7 18:00:17 localhost mtp-probe[1663]: checking bus 2, device 12: "/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4" Aug 7 18:00:17 localhost mtp-probe[1663]: bus: 2, device: 12 was not an MTP device Aug 7 18:00:18 localhost usb_modeswitch[1668]: switch device 12d1:1f1c on 002/012 Aug 7 18:00:18 localhost kernel: cdc_mbim 2-1.4:2.0: SET_NTB_FORMAT failed Aug 7 18:00:18 localhost kernel: cdc_mbim 2-1.4:2.0: bind() failure Aug 7 18:00:18 localhost kernel: usb 2-1.4: USB disconnect, device number 12 Aug 7 18:00:25 localhost kernel: usb 2-1.4: new high-speed USB device number 13 using ehci-pci Aug 7 18:00:25 localhost kernel: usb 2-1.4: New USB device found, idVendor=12d1, idProduct=14fb, bcdDevice= 1.02 Aug 7 18:00:25 localhost kernel: usb 2-1.4: New USB device strings: Mfr=2, Product=1, SerialNumber=0 Aug 7 18:00:25 localhost kernel: usb 2-1.4: Product: HUAWEI Mobile Aug 7 18:00:25 localhost kernel: usb 2-1.4: Manufacturer: HUAWEI Technology Aug 7 18:00:25 localhost mtp-probe[1672]: checking bus 2, device 13: "/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4" Aug 7 18:00:25 localhost mtp-probe[1672]: bus: 2, device: 13 was not an MTP device Aug 7 18:00:25 localhost kernel: usbcore: registered new interface driver option Aug 7 18:00:25 localhost kernel: usbserial: USB Serial support registered for GSM modem (1-port) Aug 7 18:00:25 localhost kernel: option 2-1.4:1.0: GSM modem (1-port) converter detected Aug 7 18:00:25 localhost kernel: usb 2-1.4: GSM modem (1-port) converter now attached to ttyUSB0 Aug 7 18:00:25 localhost kernel: option 2-1.4:1.1: GSM modem (1-port) converter detected Aug 7 18:00:25 localhost kernel: usb 2-1.4: GSM modem (1-port) converter now attached to ttyUSB1 Aug 7 18:00:25 localhost mtp-probe[1679]: checking bus 2, device 13: "/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4" Aug 7 18:00:25 localhost mtp-probe[1679]: bus: 2, device: 13 was not an MTP device Aug 7 18:00:38 localhost systemd[1]: usb_modeswitch@2-1.4:1.0.service: Deactivated successfully. Aug 7 18:00:38 localhost systemd[1]: Finished usb_modeswitch@2-1.4:1.0.service - USB_ModeSwitch_2-1.4:1.0. Aug 7 18:00:38 localhost audit[1]: SERVICE_START pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 msg='unit=usb_modeswitch@2-1.4:1.0 comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success' Aug 7 18:00:38 localhost audit[1]: SERVICE_STOP pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 msg='unit=usb_modeswitch@2-1.4:1.0 comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success' Aug 7 18:00:48 localhost systemd[1149]: Starting grub-boot-success.service - Mark boot as successful... Aug 7 18:00:48 localhost systemd[1149]: Finished grub-boot-success.service - Mark boot as successful. Aug 7 18:00:57 localhost ModemManager[936]: <info> [device /sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4] creating modem with plugin 'huawei' and '2' ports Aug 7 18:00:57 localhost ModemManager[936]: <warn> [plugin/huawei] could not grab port ttyUSB0: Cannot add port 'tty/ttyUSB0', unhandled port type Aug 7 18:00:57 localhost ModemManager[936]: <warn> [plugin/huawei] could not grab port ttyUSB1: Cannot add port 'tty/ttyUSB1', unhandled port type Aug 7 18:00:57 localhost ModemManager[936]: <warn> [base-manager] couldn't create modem for device '/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4': Failed to find primary AT port