The current implementation doesn't check if the subchannel is in a
proper device state when handling an event. Let's introduce
a finite state machine to manage the state/event change.
Signed-off-by: NDong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170317031743.40128-14-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>