diff --git a/drivers/infiniband/hw/amso1100/c2_qp.c b/drivers/infiniband/hw/amso1100/c2_qp.c
index 28cd5cb51859..0ab826b280b2 100644
--- a/drivers/infiniband/hw/amso1100/c2_qp.c
+++ b/drivers/infiniband/hw/amso1100/c2_qp.c
@@ -382,14 +382,17 @@ static int c2_alloc_qpn(struct c2_dev *c2dev, struct c2_qp *qp)
 {
 	int ret;
 
-        do {
-		spin_lock_irq(&c2dev->qp_table.lock);
-		ret = idr_get_new_above(&c2dev->qp_table.idr, qp,
-					c2dev->qp_table.last++, &qp->qpn);
-		spin_unlock_irq(&c2dev->qp_table.lock);
-        } while ((ret == -EAGAIN) &&
-	 	 idr_pre_get(&c2dev->qp_table.idr, GFP_KERNEL));
-	return ret;
+	idr_preload(GFP_KERNEL);
+	spin_lock_irq(&c2dev->qp_table.lock);
+
+	ret = idr_alloc(&c2dev->qp_table.idr, qp, c2dev->qp_table.last++, 0,
+			GFP_NOWAIT);
+	if (ret >= 0)
+		qp->qpn = ret;
+
+	spin_unlock_irq(&c2dev->qp_table.lock);
+	idr_preload_end();
+	return ret < 0 ? ret : 0;
 }
 
 static void c2_free_qpn(struct c2_dev *c2dev, int qpn)