Also see here.
Periodically a Xilinx dongle gets 'stuck' on a Linux node. By 'stuck', we mean that the dongle is:
...
sudo -s
on the node in question (e.g. rdusr108)cd /tmp
- Execute the script
/afs/slac/g/cci/bin/reset_cable.sh
Check to see if unplug/replug works. If not, the problem is deeper.
...