MC7455 USB device disconnects immediately

Hi,

No. I am using an embedded hardware from Compulab.

compulab.com/products/comput … /#overview

I have used the pcie slot with TELIT chips, it worked fine.

Regards,
Vinothkumar

I assume the slot on the board is configured for PCIe and not USB3 SS? Did you cover the USB3 TX/RX pins on the modem? If not, then try that.

Hi,

I tried masking the USB pins (USb3 Tx and RX pins) . I have attached the image.

Still I am facing the same issue when I connect the module over PCiE. The device enters into boot mode and loops repeatedly.

qcserial ttyUSB0: Qualcomm USB modem converter now disconnected from ttyUSB0
qcserial 1-1.3:1.0: device disconnected
usb 1-1.3: new high-speed USB device number 26 using ci_hdrc
usb 1-1.3: New USB device found, idVendor=1199, idProduct=9070
usb 1-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 1-1.3: Product: Sierra Wireless MC7455 Qualcomm
usb 1-1.3: Manufacturer: Sierra Wireless, Incorporated
usb 1-1.3: SerialNumber: LQ71660022021020
qcserial 1-1.3:1.0: Qualcomm USB modem converter detected
usb 1-1.3: Qualcomm USB modem converter now attached to ttyUSB0
usb 1-1.3: USB disconnect, device number 26
qcserial ttyUSB0: Qualcomm USB modem converter now disconnected from ttyUSB0
qcserial 1-1.3:1.0: device disconnected

Any info on the topic would be helpful.

Regards,
Vinothkumar

Vino,

I think you need to check the full pin out of the PC board you are using and compare it to the MC74 one. there may be some other incompatibility.

Regards

Matt

Hi,

After lot of tries with masking the pins, I could succesfully connect the MC7455 to my system using PCIe.

I have masked the following pins:

USB3 masking -> Pin 23,25,27,29,31,33

and also the following pins:

Pin 20 - W_DIABLE_N
Pin 22 - SYSTEM_RESET_N
Pin 24 - Vcc

I am not sure why masking these pins are necessary. Any information on side effects of masking these pins would be helpful.

Regards,
Vinothkumar

Regards,
Vinoth

Vino,

If the pins are in the wrong level or the unit is detecting activity on then not consistent with USB 3.0 then it causes issues with enumeration of the unit to the host.

Regards

Matt

I am also facing this issue using the Ubuntu 22.04 Desktop version & Kernal version 6.5.0-18-generic USB 1-1.3 Qualcomm USB modem converter MC7304 & MC7430, Pls help to resolve this issue.

What usb driver have you installed?
Can you post the kernel log when connected with the module?

Hi Thanks for the reply pls following details
Feb 22 19:47:31 lamhas-pro kernel: [ 5288.774495] qcserial 1-1.3:1 .0: Qualcomm USB modem converter detected
Feb 22 19:47:31 lamhas-pro kernel: [ 5288.774600] usb 1-1.3: Qualc omm USB modem converter now attached to ttyUSB3
Feb 22 19:47:31 lamhas-pro kernel: [ 5288.774997] qcserial 1-1.3:1 .2: Qualcomm USB modem converter detected
Feb 22 19:47:31 lamhas-pro kernel: [ 5288.775056] usb 1-1.3: Qualc omm USB modem converter now attached to ttyUSB4
Feb 22 19:47:31 lamhas-pro kernel: [ 5288.775364] qcserial 1-1.3:1 .3: Qualcomm USB modem converter detected
Feb 22 19:47:31 lamhas-pro kernel: [ 5288.775428] usb 1-1.3: Qualc omm USB modem converter now attached to ttyUSB5
Feb 22 19:47:31 lamhas-pro kernel: [ 5288.775777] qmi_wwan 1-1.3:1 .8: cdc-wdm3: USB WDM device
Feb 22 19:47:31 lamhas-pro kernel: [ 5288.776136] qmi_wwan 1-1.3:1 .8 wwan2: register ‘qmi_wwan’ at usb-0000:00:1a.0-1.3, WWAN/QMI de vice, 9a:57:24:3d:ca:c1
Feb 22 19:47:31 lamhas-pro kernel: [ 5288.776557] qmi_wwan 1-1.3:1 .10: cdc-wdm4: USB WDM device
Feb 22 19:47:31 lamhas-pro kernel: [ 5288.776832] qmi_wwan 1-1.3:1 .10 wwan3: register ‘qmi_wwan’ at usb-0000:00:1a.0-1.3, WWAN/QMI d evice, 9a:57:24:3d:ca:c1

are you installing the MBPL USB driver?
https://source.sierrawireless.com/resources/airprime/software/mbpl/mbpl-software-latest/#sthash.ZXRwiiKx.pnQ5zaB5.dpbs

What is the current issue you are facing now?

Have you tried to establish data connection with the MBPL SDK?

“I am currently using Ubuntu 22.04 and I am facing an issue where my modems keep disconnecting and reconnecting frequently. I have not installed any drivers. Can you please let me know if I need to install one? If yes, what is the procedure to do so?”

you can see this document as example:

The download page showing the latest release pls guide which one need to downloads and install for these MC7304 & MC7430 modems


?

If you want I can also provide you the remote access of the server , pls let me know if you want have a look?

MBPL_DRIVERS_R35_ENG4-bin.tar is the USB driver
MBPL_SDK_R35_ENG4-lite.bin.tar is the SDK

BTW, have you read the document?

Yes, I read the document a little while struggling with this step Install below MBPL R20 USB driver for qmi_wwan and qcserial by “make” and “make install”

Then have you installed the driver?

Trying using SDK oem@lamhas-pro:~/Downloads/MBPL_SDK_R35_ENG4-lite.bin/SampleApps/lite-qmi-connectionnnection-managerhostx86_64

lite-qmi-connection-manager v1.0.2308.1

Open transport “/dev/cdc-wdm5” on USB device in QMI mode
Interface id: 0x8
InitializeRegularService eWDA failed.EnableQmap failed.
InitializeRegularService eDMS failed.

you need to get a linux engineer to work on driver and SDK

I tried SDK it is not connecting the modems and compiling giving an error
make -C /lib/modules/6.5.0-18-generic/build/ M=/home/oem/Downloads/bin/Ubuntu_x64/5.3.0-55-generic/
make: Entering directory ‘/usr/src/linux-headers-6.5.0-18-generic’
warning: the compiler differs from the one used to build the kernel
The kernel was built by: x86_64-linux-gnu-gcc-12 (Ubuntu 12.3.0-1ubuntu1~22.04) 12.3.0
You are using: gcc-12 (Ubuntu 12.3.0-1ubuntu1~22.04) 12.3.0
scripts/Makefile.build:41: /home/oem/Downloads/bin/Ubuntu_x64/5.3.0-55-generic/Makefile: No such file or directory
make[2]: *** No rule to make target ‘/home/oem/Downloads/bin/Ubuntu_x64/5.3.0-55-generic/Makefile’. Stop.
make[1]: *** [/usr/src/linux-headers-6.5.0-18-generic/Makefile:2039: /home/oem/Downloads/bin/Ubuntu_x64/5.3.0-55-generic] Error 2
make: *** [Makefile:234: __sub-make] Error 2
make: Leaving directory ‘/usr/src/linux-headers-6.5.0-18-generic’

If you help to understand the error