Obtain an i2o message from the iop
struct i2o_message * i2o_msg_get(struct i2o_controller * c);
c
I2O controller
This function tries to get a message frame. If no message frame is available do not wait until one is available (see also i2o_msg_get_wait). The returned pointer to the message frame is not in I/O memory, it is allocated from a mempool. But because a MFA is allocated from the controller too it is guaranteed that i2o_msg_post will never fail.
On a success a pointer to the message frame is returned. If the message queue is empty -EBUSY is returned and if no memory is available -ENOMEM is returned.