TM4C123GH6ZRB: TI ROM Bootloader Enumeration Failures

Hello,

I have recently started experiencing some programming failures when working with the TI bootloader loaded in ROM on the TM4C. We have experienced this issue on both the development launchpad board, and with the IC on one of our custom boards now. I should also add that it even fails when using LMFLASHPROGRAMMER from TI and returns an error code of -1.

Below is a log showing the device failing to enumerate:

[    5.614518] hub 1-1.3.2.1:1.0: USB hub found
[    5.619131] hub 1-1.3.2.1:1.0: 4 ports detected
[    5.666698] usb 1-1.3.4: new full-speed USB device number 9 using xhci-hcd
[    5.776725] usb 1-1.3.4: device descriptor read/64, error -32
[    5.996730] usb 1-1.3.4: device descriptor read/64, error -32
[    6.216706] usb 1-1.3.4: new full-speed USB device number 10 using xhci-hcd
[    6.326731] usb 1-1.3.4: device descriptor read/64, error -32
[    6.546731] usb 1-1.3.4: device descriptor read/64, error -32
[    6.766706] usb 1-1.3.4: new full-speed USB device number 11 using xhci-hcd
[    6.776148] usb 1-1.3.4: Device not responding to setup address.
[    6.999147] usb 1-1.3.4: Device not responding to setup address.
[    7.216704] usb 1-1.3.4: device not accepting address 11, error -71
[    7.316707] usb 1-1.3.4: new full-speed USB device number 12 using xhci-hcd
[    7.326148] usb 1-1.3.4: Device not responding to setup address.
[    7.549146] usb 1-1.3.4: Device not responding to setup address.
[    7.766705] usb 1-1.3.4: device not accepting address 12, error -71
[    7.773266] usb 1-1.3-port4: unable to enumerate USB device

The device that fails to respond to setup and does not accept the address is the TM4C, as the rest of the devices attached to the hub are functioning fine.

I am running on Linux, and have tried a variety of commands to force the device to try and enumerate again, but it seems to continuously get the above error.

• • Resetting the entire hub:
    echo 0 > /sys/bus/usb/drivers/usb/1-1/authorized
    echo 1 > /sys/bus/usb/drivers/usb/1-1/authorized
  • Narrowing down to specific ports:
    echo 0 > /sys/bus/usb/drivers/usb/1-1.3/authorized
    echo 1 > /sys/bus/usb/drivers/usb/1-1.3/authorized
  • Unbinding and rebinding USB and PCI drivers
    
    for i in /sys/bus/usb/drivers/*/*:*; do

    [ -e "$i" ] || continue
    echo "${i##*/}" > "${i%/*}/unbind"
    echo "${i##*/}" > "${i%/*}/bind"
  done
   
  for i in /sys/bus/pci/drivers/*/*:*; do
    [ -e "$i" ] || continue
    echo "${i##*/}" > "${i%/*}/unbind"
    echo "${i##*/}" > "${i%/*}/bind"
  done

Are there any known issues regarding this bootloader? Or potential fixes to get around this?