[PATCH 052/115] r8169: fix vlan tag read ordering.

[Luis Henriques]

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

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

From: =?UTF-8?q?fran=C3=A7ois=20romieu?= <romieu at fr.zoreil.com>

commit ce11ff5e5963e441feb591e76278528f876c332d upstream.

Control of receive descriptor must not be returned to ethernet chipset
before vlan tag processing is done.

VLAN tag receive word is now reset both in normal and error path.

Signed-off-by: Francois Romieu <romieu at fr.zoreil.com>
Spotted-by: Timo Teras <timo.teras at iki.fi>
Cc: Hayes Wang <hayeswang at realtek.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/net/ethernet/realtek/r8169.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c
index a32d221..6c595f9 100644
--- a/drivers/net/ethernet/realtek/r8169.c
+++ b/drivers/net/ethernet/realtek/r8169.c
@@ -1687,8 +1687,6 @@ static void rtl8169_rx_vlan_tag(struct RxDesc *desc, struct sk_buff *skb)
 
 	if (opts2 & RxVlanTag)
 		__vlan_hwaccel_put_tag(skb, swab16(opts2 & 0xffff));
-
-	desc->opts2 = 0;
 }
 
 static int rtl8169_gset_tbi(struct net_device *dev, struct ethtool_cmd *cmd)
@@ -5787,8 +5785,6 @@ static int rtl_rx(struct net_device *dev, struct rtl8169_private *tp, u32 budget
 			    !(status & (RxRWT | RxFOVF)) &&
 			    (dev->features & NETIF_F_RXALL))
 				goto process_pkt;
-
-			rtl8169_mark_to_asic(desc, rx_buf_sz);
 		} else {
 			struct sk_buff *skb;
 			dma_addr_t addr;
@@ -5809,16 +5805,14 @@ process_pkt:
 			if (unlikely(rtl8169_fragmented_frame(status))) {
 				dev->stats.rx_dropped++;
 				dev->stats.rx_length_errors++;
-				rtl8169_mark_to_asic(desc, rx_buf_sz);
-				continue;
+				goto release_descriptor;
 			}
 
 			skb = rtl8169_try_rx_copy(tp->Rx_databuff[entry],
 						  tp, pkt_size, addr);
-			rtl8169_mark_to_asic(desc, rx_buf_sz);
 			if (!skb) {
 				dev->stats.rx_dropped++;
-				continue;
+				goto release_descriptor;
 			}
 
 			rtl8169_rx_csum(skb, status);
@@ -5834,6 +5828,10 @@ process_pkt:
 			tp->rx_stats.bytes += pkt_size;
 			u64_stats_update_end(&tp->rx_stats.syncp);
 		}
+release_descriptor:
+		desc->opts2 = 0;
+		wmb();
+		rtl8169_mark_to_asic(desc, rx_buf_sz);
 	}
 
 	count = cur_rx - tp->cur_rx;
-- 
1.8.1.2