IB/ipath: Fix hang on module unload

Handle the case where posting a send is requested when the link is
down.  This fixes <https://bugs.openfabrics.org/show_bug.cgi?id=1117>.
Signed-off-by: Yannick Cote <yannick.cote@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/hw/ipath/ipath_verbs.c

@@ -340,9 +340,16 @@ static int ipath_post_one_send(struct ipath_qp *qp, struct ib_send_wr *wr)
 	int acc;
 	int ret;
 	unsigned long flags;
+	struct ipath_devdata *dd = to_idev(qp->ibqp.device)->dd;
 
 	spin_lock_irqsave(&qp->s_lock, flags);
 
+	if (qp->ibqp.qp_type != IB_QPT_SMI &&
+	    !(dd->ipath_flags & IPATH_LINKACTIVE)) {
+		ret = -ENETDOWN;
+		goto bail;
+	}
+
 	/* Check that state is OK to post send. */
 	if (unlikely(!(ib_ipath_state_ops[qp->state] & IPATH_POST_SEND_OK)))
 		goto bail_inval;