Getting a TI Launchpad MSP430's serial connection to work under Linux is a pain. This is what worked for me under a recent kernel (3.12.8-300) under Fedora 20.
Simply run "make", and if it builds you should back up your cdc-acm.ko module somewhere and replace it with the one you just built, then run "depmod -a" and replug your device.
If it doesn't work you probably have the wrong kernel version. Check the references below.
Run this command to find where your should replace the cdc-acm.ko file.
echo /lib/modules/$(uname -r)/kernel/drivers/usb/class/
My board is a rev 1.5 with a MSP430G2553. I did NOT cross the TXD/RXD jumpers, they are in the original position.
- https://github.com/capnm/LaunchPad Original source of this fix. If your kernel is older you should try this instead. Also contains udev rules which you should probably check out.