Cause

During a read(2), getmsg(2), or ioctl(2) I_RECVFD call to a STREAMS device, some data has come to the head of the queue that cannot be processed. That data depends on the call:

1. read(2) -- Controls information or passes a file descriptor

2. getmsg(2) -- Passes a file descriptor

3. ioctl(2) -- Controls data information