[PATCH 4.4 048/137] sh_eth: advance rxdesc later in sh_eth_ring_format()

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx>

[ Upstream commit d0ba913488dc8c55d1880f5ed34f096dc45fb05d ]

Iff dma_map_single() fails, 'rxdesc'  should point  to the last filled RX
descriptor, so  that it can be marked as the last one, however the driver
would have  already  advanced it by that time. In order to fix that, only
fill  an RX descriptor  once all the data for it is ready.

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/renesas/sh_eth.c |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

--- a/drivers/net/ethernet/renesas/sh_eth.c
+++ b/drivers/net/ethernet/renesas/sh_eth.c
@@ -1185,11 +1185,8 @@ static void sh_eth_ring_format(struct ne
 			break;
 		sh_eth_set_receive_align(skb);
 
-		/* RX descriptor */
-		rxdesc = &mdp->rx_ring[i];
 		/* The size of the buffer is a multiple of 32 bytes. */
 		buf_len = ALIGN(mdp->rx_buf_sz, 32);
-		rxdesc->len = cpu_to_edmac(mdp, buf_len << 16);
 		dma_addr = dma_map_single(&ndev->dev, skb->data, buf_len,
 					  DMA_FROM_DEVICE);
 		if (dma_mapping_error(&ndev->dev, dma_addr)) {
@@ -1197,6 +1194,10 @@ static void sh_eth_ring_format(struct ne
 			break;
 		}
 		mdp->rx_skbuff[i] = skb;
+
+		/* RX descriptor */
+		rxdesc = &mdp->rx_ring[i];
+		rxdesc->len = cpu_to_edmac(mdp, buf_len << 16);
 		rxdesc->addr = cpu_to_edmac(mdp, dma_addr);
 		rxdesc->status = cpu_to_edmac(mdp, RD_RACT | RD_RFP);