r8169: add byte queue limit support.

Nothing fancy:
- sent bytes count is notified in the start_xmit path right before
  updating the owner bit in the hardware Tx descriptor (E. Dumazet)
- avoid useless tp->dev dereferencing in start_xmit (E. Dumazet)

Use of netdev_reset_queue is favored over proper accounting in
rtl8169_tx_clear_range since the latter would need more work for the
same result (nb: said accounting degenerates to nothing in xmit_frags).

Signed-off-by: Igor Maravic <igorm@etf.rs>
Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>

1 files changed, 22 insertions, 5 deletions

diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c
index a4d7674886a2..515a7edb605c 100644
--- a/drivers/net/ethernet/realtek/r8169.c
+++ b/drivers/net/ethernet/realtek/r8169.c
@@ -5399,6 +5399,7 @@ static void rtl8169_tx_clear(struct rtl8169_private *tp)
 {
         rtl8169_tx_clear_range(tp, tp->dirty_tx, NUM_TX_DESC);
         tp->cur_tx = tp->dirty_tx = 0;
+        netdev_reset_queue(tp->dev);
 }
 
 static void rtl_reset_work(struct rtl8169_private *tp)
@@ -5553,6 +5554,8 @@ static netdev_tx_t rtl8169_start_xmit(struct sk_buff *skb,
 
         txd->opts2 = cpu_to_le32(opts[1]);
 
+        netdev_sent_queue(dev, skb->len);
+
         wmb();
 
         /* Anti gcc 2.95.3 bugware (sic) */
@@ -5647,9 +5650,16 @@ static void rtl8169_pcierr_interrupt(struct net_device *dev)
         rtl_schedule_task(tp, RTL_FLAG_TASK_RESET_PENDING);
 }
 
+struct rtl_txc {
+        int packets;
+        int bytes;
+};
+
 static void rtl_tx(struct net_device *dev, struct rtl8169_private *tp)
 {
+        struct rtl8169_stats *tx_stats = &tp->tx_stats;
         unsigned int dirty_tx, tx_left;
+        struct rtl_txc txc = { 0, 0 };
 
         dirty_tx = tp->dirty_tx;
         smp_rmb();
@@ -5668,17 +5678,24 @@ static void rtl_tx(struct net_device *dev, struct rtl8169_private *tp)
                 rtl8169_unmap_tx_skb(&tp->pci_dev->dev, tx_skb,
                                      tp->TxDescArray + entry);
                 if (status & LastFrag) {
-                        u64_stats_update_begin(&tp->tx_stats.syncp);
-                        tp->tx_stats.packets++;
-                        tp->tx_stats.bytes += tx_skb->skb->len;
-                        u64_stats_update_end(&tp->tx_stats.syncp);
-                        dev_kfree_skb(tx_skb->skb);
+                        struct sk_buff *skb = tx_skb->skb;
+
+                        txc.packets++;
+                        txc.bytes += skb->len;
+                        dev_kfree_skb(skb);
                         tx_skb->skb = NULL;
                 }
                 dirty_tx++;
                 tx_left--;
         }
 
+        u64_stats_update_begin(&tx_stats->syncp);
+        tx_stats->packets += txc.packets;
+        tx_stats->bytes += txc.bytes;
+        u64_stats_update_end(&tx_stats->syncp);
+
+        netdev_completed_queue(dev, txc.packets, txc.bytes);
+
         if (tp->dirty_tx != dirty_tx) {
                 tp->dirty_tx = dirty_tx;
                 /* Sync with rtl8169_start_xmit: