r8169: fix vlan tag read ordering.

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@fr.zoreil.com>
Spotted-by: Timo Teras <timo.teras@iki.fi>
Cc: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c
index f69ca462464445da1ea5d2eebb63742bb7a18b19..f698183859b06c51dd63e5d84afbc111edc7c06c 100644 (file)
--- a/drivers/net/ethernet/realtek/r8169.c
+++ b/drivers/net/ethernet/realtek/r8169.c
@@ -1629,8 +1629,6 @@ 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)
@@ -5823,7 +5821,6 @@ static int rtl8169_rx_interrupt(struct net_device *dev,
                                rtl8169_schedule_work(dev, rtl8169_reset_task);
                                dev->stats.rx_fifo_errors++;
                        }
-                       rtl8169_mark_to_asic(desc, rx_buf_sz);
                } else {
                        struct sk_buff *skb;
                        dma_addr_t addr = le64_to_cpu(desc->addr);
@@ -5837,16 +5834,14 @@ static int rtl8169_rx_interrupt(struct net_device *dev,
                        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);
@@ -5860,6 +5855,10 @@ static int rtl8169_rx_interrupt(struct net_device *dev,
                        dev->stats.rx_bytes += pkt_size;
                        dev->stats.rx_packets++;
                }
+release_descriptor:
+               desc->opts2 = 0;
+               wmb();
+               rtl8169_mark_to_asic(desc, rx_buf_sz);
        }
 
        count = cur_rx - tp->cur_rx;