Having problem with brown driver?

edit

while running brown driver following is the problem

$ rosrun irobot_create_2_1 driver.py

Traceback (most recent call last):
File "/opt/ros/groovy/stacks/brown_drivers/irobot_create_2_1/bin/driver.py", line 138, in <module>
driver = CreateDriver()
File "/opt/ros/groovy/stacks/brown_drivers/irobot_create_2_1/bin/driver.py", line 21, in __init__
self.create = Create(port)
File "/opt/ros/groovy/stacks/brown_drivers/irobot_create_2_1/bin/irobot/create.py", line 144, in __init__
self.reset()
File "/opt/ros/groovy/stacks/brown_drivers/irobot_create_2_1/bin/irobot/create.py", line 175, in reset
self.__read(128,True)
File "/opt/ros/groovy/stacks/brown_drivers/irobot_create_2_1/bin/irobot/create.py", line 221, in __read
bytes = self.port.read(num)
File "/usr/local/lib/python2.7/dist-packages/pyserial-2.6-py2.7.egg/serial/serialposix.py", line 446, in read
ready,_,_ = select.select([self.fd],[],[], self._timeout)
select.error: (4, 'Interrupted system call')