IPoIB: Include return code in trace message for ib_post_send() failures

Print the return code of ib_post_send() if it fails to make these
debugging messages more useful.

Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/ulp/ipoib/ipoib_cm.c

@@ -708,6 +708,7 @@ void ipoib_cm_send(struct net_device *dev, struct sk_buff *skb, struct ipoib_cm_
 	struct ipoib_dev_priv *priv = netdev_priv(dev);
 	struct ipoib_cm_tx_buf *tx_req;
 	u64 addr;
+	int rc;
 
 	if (unlikely(skb->len > tx->mtu)) {
 		ipoib_warn(priv, "packet len %d (> %d) too long to send, dropping\n",
@@ -739,9 +740,10 @@ void ipoib_cm_send(struct net_device *dev, struct sk_buff *skb, struct ipoib_cm_
 
 	tx_req->mapping = addr;
 
-	if (unlikely(post_send(priv, tx, tx->tx_head & (ipoib_sendq_size - 1),
-			       addr, skb->len))) {
-		ipoib_warn(priv, "post_send failed\n");
+	rc = post_send(priv, tx, tx->tx_head & (ipoib_sendq_size - 1),
+		       addr, skb->len);
+	if (unlikely(rc)) {
+		ipoib_warn(priv, "post_send failed, error %d\n", rc);
 		++dev->stats.tx_errors;
 		ib_dma_unmap_single(priv->ca, addr, skb->len, DMA_TO_DEVICE);
 		dev_kfree_skb_any(skb);

drivers/infiniband/ulp/ipoib/ipoib_ib.c

@@ -529,7 +529,7 @@ void ipoib_send(struct net_device *dev, struct sk_buff *skb,
 {
 	struct ipoib_dev_priv *priv = netdev_priv(dev);
 	struct ipoib_tx_buf *tx_req;
-	int hlen;
+	int hlen, rc;
 	void *phead;
 
 	if (skb_is_gso(skb)) {
@@ -585,9 +585,10 @@ void ipoib_send(struct net_device *dev, struct sk_buff *skb,
 		netif_stop_queue(dev);
 	}
 
-	if (unlikely(post_send(priv, priv->tx_head & (ipoib_sendq_size - 1),
-			       address->ah, qpn, tx_req, phead, hlen))) {
-		ipoib_warn(priv, "post_send failed\n");
+	rc = post_send(priv, priv->tx_head & (ipoib_sendq_size - 1),
+		       address->ah, qpn, tx_req, phead, hlen);
+	if (unlikely(rc)) {
+		ipoib_warn(priv, "post_send failed, error %d\n", rc);
 		++dev->stats.tx_errors;
 		--priv->tx_outstanding;
 		ipoib_dma_unmap_tx(priv->ca, tx_req);