diff --git a/drivers/infiniband/hw/cxgb4/qp.c b/drivers/infiniband/hw/cxgb4/qp.c
index 892fa7c..62c7262 100644
--- a/drivers/infiniband/hw/cxgb4/qp.c
+++ b/drivers/infiniband/hw/cxgb4/qp.c
@@ -941,8 +941,11 @@
 	flushed = c4iw_flush_rq(&qhp->wq, &rchp->cq, count);
 	spin_unlock(&qhp->lock);
 	spin_unlock_irqrestore(&rchp->lock, flag);
-	if (flushed)
+	if (flushed) {
+		spin_lock_irqsave(&rchp->comp_handler_lock, flag);
 		(*rchp->ibcq.comp_handler)(&rchp->ibcq, rchp->ibcq.cq_context);
+		spin_unlock_irqrestore(&rchp->comp_handler_lock, flag);
+	}
 
 	/* locking hierarchy: cq lock first, then qp lock. */
 	spin_lock_irqsave(&schp->lock, flag);
@@ -952,13 +955,17 @@
 	flushed = c4iw_flush_sq(&qhp->wq, &schp->cq, count);
 	spin_unlock(&qhp->lock);
 	spin_unlock_irqrestore(&schp->lock, flag);
-	if (flushed)
+	if (flushed) {
+		spin_lock_irqsave(&schp->comp_handler_lock, flag);
 		(*schp->ibcq.comp_handler)(&schp->ibcq, schp->ibcq.cq_context);
+		spin_unlock_irqrestore(&schp->comp_handler_lock, flag);
+	}
 }
 
 static void flush_qp(struct c4iw_qp *qhp)
 {
 	struct c4iw_cq *rchp, *schp;
+	unsigned long flag;
 
 	rchp = get_chp(qhp->rhp, qhp->attr.rcq);
 	schp = get_chp(qhp->rhp, qhp->attr.scq);
@@ -966,11 +973,15 @@
 	if (qhp->ibqp.uobject) {
 		t4_set_wq_in_error(&qhp->wq);
 		t4_set_cq_in_error(&rchp->cq);
+		spin_lock_irqsave(&rchp->comp_handler_lock, flag);
 		(*rchp->ibcq.comp_handler)(&rchp->ibcq, rchp->ibcq.cq_context);
+		spin_unlock_irqrestore(&rchp->comp_handler_lock, flag);
 		if (schp != rchp) {
 			t4_set_cq_in_error(&schp->cq);
+			spin_lock_irqsave(&schp->comp_handler_lock, flag);
 			(*schp->ibcq.comp_handler)(&schp->ibcq,
 					schp->ibcq.cq_context);
+			spin_unlock_irqrestore(&schp->comp_handler_lock, flag);
 		}
 		return;
 	}