Bringing up new 4G Sierra Wireless issue


#1

I am trying to bring a Sierra Wireless HL7588 chip online. The HL7588 creates a ttyACM under /dev, rather than ttyUSB. The /dev/cdc-wdm0 handle does not get created. I am able to connect to the ttyACM0 handle and send AT commands to the chip, so OpenWRT is able to communicate with the device.

Since the cdc-wdm0 is not created the qmi interface is not active and there is no active connection created with the carrier and no IP allocated.

Can anyone provide some guidance on what is missing in the configuration to bring this chip up on QMI?

Jonathan


#2

Have you read https://openwrt.org/docs/guide-user/network/wan/wwan/ltedongle already?


#3

Maybe HL7588 is so new and not added to yours kernel version qmi driver. You can add it yourself if you know vendor and product IDs. This information you can find from cat /sys/kernel/debug/usb/devices

echo "vendor product" > /sys/bus/usb/drivers/qmi_wwan/new_id

#4

Yes, more than once. I have been able to get the device to create the /dev/cdc-wdm0 device, but now I am stuck there. Information on the umbim module is sparse to non-existent. All of the return information is in hex format and I can not find documents on how to translate the returned info. I have verified, that although the APN is set, I do not get an IP address.


#5

I don't know the HL7588. Is it supported as a QMI device by the Sierra Wireless GobiNet driver? Is the USB layout configurable? If so, are you sure at least one QMI (or RMNET) funtion is enabled? Can you provide "lsusb -v" or "cat /sys/kernel/debug/usb/devices" showing the current USB layout.