HL7648 USB connect/disconnects


#1

Hello all,
I’m bringing up a HL7648 based solution/drop-in replacement connected with a RPi3 over a USB-to-serial connection. However, I am observing continuous USB connects/disconnects every 6 seconds with the same product/manufacturing information (which I am guessing is the HL fsbl):
[ 109.803796] usb 1-1.4: new high-speed USB device number 4 using dwc_otg
[ 109.935011] usb 1-1.4: New USB device found, idVendor=8087, idProduct=0716
[ 109.935024] usb 1-1.4: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[ 113.856125] usb 1-1.4: USB disconnect, device number 4
[ 116.963896] usb 1-1.4: new high-speed USB device number 5 using dwc_otg
[ 117.095119] usb 1-1.4: New USB device found, idVendor=8087, idProduct=0716
[ 117.095133] usb 1-1.4: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[ 120.000130] usb 1-1.4: USB disconnect, device number 5

On a different prototype board with the same linux kernel distribution and Sierra wireless module, I get the same initial USB connect/disconnect pattern the first time followed by a second USB iteration where it correctly identifies itself as a sierra wireless module that I am attempting to interface with:
[ 397.404111] usb 1-1.4: new high-speed USB device number 7 using dwc_otg
[ 397.535336] usb 1-1.4: New USB device found, idVendor=8087, idProduct=0716
[ 397.535350] usb 1-1.4: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[ 400.440473] usb 1-1.4: USB disconnect, device number 7
[ 403.554056] usb 1-1.4: new high-speed USB device number 8 using dwc_otg
[ 403.696948] usb 1-1.4: New USB device found, idVendor=1519, idProduct=0443
[ 403.696963] usb 1-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 403.696971] usb 1-1.4: Product: SWIMCB71XX
[ 403.696979] usb 1-1.4: Manufacturer: Sierra Wireless Inc.
[ 403.696986] usb 1-1.4: SerialNumber: 014697000056835
[ 403.732254] cdc_acm 1-1.4:1.0: ttyACM0: USB ACM device
[ 403.735762] cdc_acm 1-1.4:1.2: ttyACM1: USB ACM device
[ 403.738892] cdc_acm 1-1.4:1.4: ttyACM2: USB ACM device

Does anyone recognize this behavior? Is it a possible clue on what component or configuration may be preventing the module from successfully registering itself over USB with the Linux kernel as a Sierra Wireless device?

Thanks for any input…
Mark M


#2

Hi Mark ,
It seems your module does not start up or always reboots. (VID/PID USB: 8087/0716 is for Flash download. 1519/0443 is for normal mode).
Pleases check first with your power supply.


#3

Thanks,
We had an issue with Vref - it was toggling on/off with the state of the POWER_ON_OFF control I/o - having Vref held static at the desired voltage value certainly helps.

Mark M