Linux/CCSTUDIO: XDS200 "Test connection" usually fails under Linux

Tool/software: Linux

I am seldom able to connect to an XDS200 in Linux. 

1. Ubuntu 18.04
2. CCS 8.3.1
3. Ran ~/ti/ccsv8/install_scripts/install_drivers.sh
4. Same files work under Windows.
5. OMAP L138 custom board, but uses LCDKOMAPL138
6. testBoard.dat and LCDKOMAPL138.ccxml  identical to Windows 10 that works.
7. lsusb output: Bus 001 Device 002: ID 0451:bef0 Texas Instruments, Inc.
8. /dev/ttyACM0 and /dev/ttyACM1 appear and disappear when emulator is plugged in. Green LED on emulator is lit.

The "Test Connection" button runs the command:

%ccs_base%/common/uscif/dbgjtag -f %boarddatafile% -rv -o -S integrity

This expands to:

dbgjtag -f ~/.ti/ti/0/0/BrdDat/testBoard.dat -rv -o -S integrity

"testBoard.dat" is identical to version that works under Linux.

Running this command manually, or in CCS hangs and no further output is seen after it runs.

I have been able to run the dbgjtag command one time after rebooting on occasion.  I seem to be able to reliably reproduce it by:

Editing /etc/udev/rules.d/71-ti-permissions.rules.

Adding the entry:

SUBSYSTEM=="usb",ENV{DEVTYPE}=="usb_device",ATTRS{idVendor}=="0451",ATTRS{idProduct}=="bef0",MODE:="0666"

And commenting out the line:

#ATTRS{idVendor}=="0451",ATTRS{idProduct}=="bef0",ENV{ID_MM_DEVICE_IGNORE}="1"

After rebooting, I can execute the dbgjtag (above) command once and get a scan successful output.  Also, I can load and debug a C6XXX program into my board.

After disconnecting the emulator USB connection, or rebooting, it does not work again.

To get it to work again, I must copy the original, unmodified udev rules and reboot.  Then copy the "fixed" one and reboot again, then it will work once, (emulator already plugged in). I have tried this twice and it worked both times. This may explain  why re-running install_drivers.sh sometimes appeared to solve my problem when trying other versions of CCS.

Setting udevd to log to syslog, I believe I see the following when it works:

May 23 07:45:15 fir kernel: [ 511.306684] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
May 23 07:45:15 fir kernel: [ 511.306685] usb 1-1: Product: XDS2xx USB Emulator - Composit
May 23 07:45:15 fir kernel: [ 511.306686] usb 1-1: Manufacturer: Spectrum Digital
May 23 07:45:15 fir kernel: [ 511.306686] usb 1-1: SerialNumber: S200-000E99039000
May 23 07:45:15 fir kernel: [ 511.316786] cdc_acm 1-1:1.0: ttyACM0: USB ACM device
May 23 07:45:15 fir kernel: [ 511.316975] cdc_acm 1-1:1.2: ttyACM1: USB ACM device
May 23 07:45:15 fir kernel: [ 511.317102] usbcore: registered new interface driver cdc_acm
May 23 07:45:15 fir kernel: [ 511.317103] cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters

Most of the time, when it does NOT work, I see:

May 23 08:05:13 fir ModemManager[1072]: <info> [device /sys/devices/pci0000:00/0000:00:14.0/usb1/1-1] creating modem with plugin 'Generic' and '2' ports
May 23 08:05:13 fir ModemManager[1072]: <warn> Could not grab port (tty/ttyACM1): 'Cannot add port 'tty/ttyACM1', unhandled serial type'
May 23 08:05:13 fir ModemManager[1072]: <warn> Could not grab port (tty/ttyACM0): 'Cannot add port 'tty/ttyACM0', unhandled serial type'

I can send the entire syslog which includes the udev ACM0 and ACM1 messages.