MC7455 bootloop

Hi, I have a problem with mc7455. My modem went into a bootloop. In Windows, I don’t see the device at all, no usb, no com ports, no network card. But in ubuntu, I began to notice that when I run the lsusb command, I see that it comes to life for 40-60 seconds. Also I see available ttyUSB:
ttyUSB0
ttyUSB1
ttyUSB2
I’m using cutecom to connect, but none of the ttyUSB’s are responding to my AT commands. As I said, after 40-60 seconds the modem goes into reboot again and after ~ 2 minutes it will become available again.
I really need help in solving this problem.

What did you see in dmesg in linux?
What if you do firmware update before it reboots?

Thanks for your answer, here is what I have in dmesg:

10131.457082] usb 2-1.8: new high-speed USB device number 79 using ehci-pci
[10131.565778] usb 2-1.8: config 1 has an invalid interface number: 12 but max is 4
[10131.565785] usb 2-1.8: config 1 has an invalid interface number: 13 but max is 4
[10131.565786] usb 2-1.8: config 1 has an invalid interface number: 13 but max is 4
[10131.565788] usb 2-1.8: config 1 has no interface number 1
[10131.565790] usb 2-1.8: config 1 has no interface number 4
[10131.566260] usb 2-1.8: New USB device found, idVendor=1199, idProduct=9071, bcdDevice= 0.06
[10131.566264] usb 2-1.8: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[10131.566266] usb 2-1.8: Product: Sierra Wireless MC7455 Qualcomm® Snapdragon™ X7 LTE-A
[10131.566268] usb 2-1.8: Manufacturer: Sierra Wireless, Incorporated
[10131.567052] qcserial 2-1.8:1.0: Qualcomm USB modem converter detected
[10131.567195] usb 2-1.8: Qualcomm USB modem converter now attached to ttyUSB0
[10131.567433] qcserial 2-1.8:1.2: Qualcomm USB modem converter detected
[10131.567537] usb 2-1.8: Qualcomm USB modem converter now attached to ttyUSB1
[10131.568288] qcserial 2-1.8:1.3: Qualcomm USB modem converter detected
[10131.568394] usb 2-1.8: Qualcomm USB modem converter now attached to ttyUSB2
[10131.593532] cdc_mbim 2-1.8:1.12: cdc-wdm0: USB WDM device
[10131.593944] cdc_mbim 2-1.8:1.12 wwan0: register 'cdc_mbim' at usb-0000:00:1d.0-1.8, CDC MBIM, 4e:57:ee:27:a4:e3
[10189.315163] usb 2-1.8: USB disconnect, device number 79
[10189.315415] qcserial ttyUSB0: Qualcomm USB modem converter now disconnected from ttyUSB0
[10189.315449] qcserial 2-1.8:1.0: device disconnected
[10189.321274] qcserial ttyUSB1: Qualcomm USB modem converter now disconnected from ttyUSB1
[10189.321311] qcserial 2-1.8:1.2: device disconnected
[10189.323253] qcserial ttyUSB2: Qualcomm USB modem converter now disconnected from ttyUSB2
[10189.323280] qcserial 2-1.8:1.3: device disconnected
[10189.324390] cdc_mbim 2-1.8:1.12 wwan0: unregister 'cdc_mbim' usb-0000:00:1d.0-1.8, CDC MBIM
[10258.619545] usb 2-1.8: new high-speed USB device number 80 using ehci-pci
[10258.733078] usb 2-1.8: config 1 has an invalid interface number: 12 but max is 4
[10258.733091] usb 2-1.8: config 1 has an invalid interface number: 13 but max is 4
[10258.733097] usb 2-1.8: config 1 has an invalid interface number: 13 but max is 4
[10258.733103] usb 2-1.8: config 1 has no interface number 1
[10258.733108] usb 2-1.8: config 1 has no interface number 4
[10258.733567] usb 2-1.8: New USB device found, idVendor=1199, idProduct=9071, bcdDevice= 0.06
[10258.733574] usb 2-1.8: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[10258.733578] usb 2-1.8: Product: Sierra Wireless MC7455 Qualcomm® Snapdragon™ X7 LTE-A
[10258.733581] usb 2-1.8: Manufacturer: Sierra Wireless, Incorporated
[10258.734489] qcserial 2-1.8:1.0: Qualcomm USB modem converter detected
[10258.734621] usb 2-1.8: Qualcomm USB modem converter now attached to ttyUSB0
[10258.734860] qcserial 2-1.8:1.2: Qualcomm USB modem converter detected
[10258.734987] usb 2-1.8: Qualcomm USB modem converter now attached to ttyUSB1
[10258.735280] qcserial 2-1.8:1.3: Qualcomm USB modem converter detected
[10258.735420] usb 2-1.8: Qualcomm USB modem converter now attached to ttyUSB2
[10258.755928] cdc_mbim 2-1.8:1.12: cdc-wdm0: USB WDM device
[10258.756350] cdc_mbim 2-1.8:1.12 wwan0: register 'cdc_mbim' at usb-0000:00:1d.0-1.8, CDC MBIM, 4e:57:ee:27:a4:e3
[10316.495415] usb 2-1.8: USB disconnect, device number 80
[10316.495701] qcserial ttyUSB0: Qualcomm USB modem converter now disconnected from ttyUSB0
[10316.495732] qcserial 2-1.8:1.0: device disconnected
[10316.496452] qcserial ttyUSB1: Qualcomm USB modem converter now disconnected from ttyUSB1
[10316.496483] qcserial 2-1.8:1.2: device disconnected
[10316.496723] qcserial ttyUSB2: Qualcomm USB modem converter now disconnected from ttyUSB2
[10316.496751] qcserial 2-1.8:1.3: device disconnected
[10316.496827] cdc_mbim 2-1.8:1.12 wwan0: unregister 'cdc_mbim' usb-0000:00:1d.0-1.8, CDC MBIM
[10385.849928] usb 2-1.8: new high-speed USB device number 81 using ehci-pci
[10385.959169] usb 2-1.8: config 1 has an invalid interface number: 12 but max is 4
[10385.959178] usb 2-1.8: config 1 has an invalid interface number: 13 but max is 4
[10385.959181] usb 2-1.8: config 1 has an invalid interface number: 13 but max is 4
[10385.959183] usb 2-1.8: config 1 has no interface number 1
[10385.959186] usb 2-1.8: config 1 has no interface number 4
[10385.959777] usb 2-1.8: New USB device found, idVendor=1199, idProduct=9071, bcdDevice= 0.06
[10385.959785] usb 2-1.8: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[10385.959789] usb 2-1.8: Product: Sierra Wireless MC7455 Qualcomm® Snapdragon™ X7 LTE-A
[10385.959793] usb 2-1.8: Manufacturer: Sierra Wireless, Incorporated
[10385.960674] qcserial 2-1.8:1.0: Qualcomm USB modem converter detected
[10385.960868] usb 2-1.8: Qualcomm USB modem converter now attached to ttyUSB0
[10385.961168] qcserial 2-1.8:1.2: Qualcomm USB modem converter detected
[10385.961279] usb 2-1.8: Qualcomm USB modem converter now attached to ttyUSB1
[10385.962288] qcserial 2-1.8:1.3: Qualcomm USB modem converter detected
[10385.962442] usb 2-1.8: Qualcomm USB modem converter now attached to ttyUSB2
[10385.982392] cdc_mbim 2-1.8:1.12: cdc-wdm0: USB WDM device
[10385.982661] cdc_mbim 2-1.8:1.12 wwan0: register 'cdc_mbim' at usb-0000:00:1d.0-1.8, CDC MBIM, 4e:57:ee:27:a4:e3
[10443.754381] usb 2-1.8: USB disconnect, device number 81
[10443.754609] qcserial ttyUSB0: Qualcomm USB modem converter now disconnected from ttyUSB0
[10443.754641] qcserial 2-1.8:1.0: device disconnected
[10443.754816] qcserial ttyUSB1: Qualcomm USB modem converter now disconnected from ttyUSB1
[10443.754840] qcserial 2-1.8:1.2: device disconnected
[10443.755049] qcserial ttyUSB2: Qualcomm USB modem converter now disconnected from ttyUSB2
[10443.755071] qcserial 2-1.8:1.3: device disconnected
[10443.755197] cdc_mbim 2-1.8:1.12 wwan0: unregister 'cdc_mbim' usb-0000:00:1d.0-1.8, CDC MBIM
[10512.968565] usb 2-1.8: new high-speed USB device number 82 using ehci-pci
[10513.077814] usb 2-1.8: config 1 has an invalid interface number: 12 but max is 4
[10513.077824] usb 2-1.8: config 1 has an invalid interface number: 13 but max is 4
[10513.077827] usb 2-1.8: config 1 has an invalid interface number: 13 but max is 4
[10513.077830] usb 2-1.8: config 1 has no interface number 1
[10513.077833] usb 2-1.8: config 1 has no interface number 4
[10513.078367] usb 2-1.8: New USB device found, idVendor=1199, idProduct=9071, bcdDevice= 0.06
[10513.078373] usb 2-1.8: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[10513.078377] usb 2-1.8: Product: Sierra Wireless MC7455 Qualcomm® Snapdragon™ X7 LTE-A
[10513.078379] usb 2-1.8: Manufacturer: Sierra Wireless, Incorporated
[10513.079596] qcserial 2-1.8:1.0: Qualcomm USB modem converter detected
[10513.079716] usb 2-1.8: Qualcomm USB modem converter now attached to ttyUSB0
[10513.080351] qcserial 2-1.8:1.2: Qualcomm USB modem converter detected
[10513.080630] usb 2-1.8: Qualcomm USB modem converter now attached to ttyUSB1
[10513.081018] qcserial 2-1.8:1.3: Qualcomm USB modem converter detected
[10513.081124] usb 2-1.8: Qualcomm USB modem converter now attached to ttyUSB2
[10513.101906] cdc_mbim 2-1.8:1.12: cdc-wdm0: USB WDM device
[10513.102341] cdc_mbim 2-1.8:1.12 wwan0: register 'cdc_mbim' at usb-0000:00:1d.0-1.8, CDC MBIM, 4e:57:ee:27:a4:e3
[10571.102236] usb 2-1.8: USB disconnect, device number 82
[10571.102530] qcserial ttyUSB0: Qualcomm USB modem converter now disconnected from ttyUSB0
[10571.102556] qcserial 2-1.8:1.0: device disconnected
[10571.102816] qcserial ttyUSB1: Qualcomm USB modem converter now disconnected from ttyUSB1
[10571.102842] qcserial 2-1.8:1.2: device disconnected
[10571.103050] qcserial ttyUSB2: Qualcomm USB modem converter now disconnected from ttyUSB2
[10571.103076] qcserial 2-1.8:1.3: device disconnected
[10571.103142] cdc_mbim 2-1.8:1.12 wwan0: unregister 'cdc_mbim' usb-0000:00:1d.0-1.8, CDC MBIM

I tried to apply qmi-firmware-update with different options:

krosor47@maindesktop:/dev$ sudo qmi-firmware-update --tty=/dev/ttyUSB2 -u '/home/krosor47/Download /firmware/SWI9X30C_02.38.00.00.cwe' --device-open-auto
loading device information before update...
error: couldn't open QMI device: Operation timed out: device is closed

the same error with the choice of port ttyUSB1 and ttyUSB0.

Tried resetting to download mode:

krosor47@maindesktop:/dev$ sudo qmi-firmware-update --tty=/dev/ttyUSB2 --reset
error: reset operation finished: couldn't run reset operation

the same error with the choice of port ttyUSB1 and ttyUSB0.

I also tried to use the identifier for the cdc-wdm0 modem:

sudo qmi-firmware-update --cdc-wdm=/dev/cdc-wdm0 -u '/home/krosor47/Download /firmware/SWI9X30C_02.38.00.00.cwe'
loading device information before update...
error: couldn't open QMI device: Operation timed out: device is closed

All these attempts were also supplemented with the --device-open-mbim parameter
Then I tried --device-open-qmi
And last --device-open-auto

I’m doing something wrong, but I can’t figure out what it is. Thanks in advance for your help!

how about using the fwdwl application?

https://source.sierrawireless.com/resources/airprime/software/mbpl/mbpl-software-latest/#sthash.3CU1T07j.dpbs

Can you elaborate more? I am not sure how to install the mbpl software. I am running into the same issue as OP.

Just download the usb driver and fwdwl in your linux

You can see the pdf document here

https://source.sierrawireless.com/resources/airprime/software/mbpl/mbpl-software-latest/