r8169: add support for xmit_more

Delay update of hw tail descriptor if we know that another skb is going
to be sent.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c
index 14a1c5cec3a59fc8699858a507ca3b077b45981b..3a280598a15a1d9fbe34c437c9cfb2b8c07fe06a 100644 (file)
--- a/drivers/net/ethernet/realtek/r8169.c
+++ b/drivers/net/ethernet/realtek/r8169.c
@@ -7049,6 +7049,7 @@ static netdev_tx_t rtl8169_start_xmit(struct sk_buff *skb,
        u32 status, len;
        u32 opts[2];
        int frags;
+       bool stop_queue;
 
        if (unlikely(!TX_FRAGS_READY_FOR(tp, skb_shinfo(skb)->nr_frags))) {
                netif_err(tp, drv, dev, "BUG! Tx Ring full when queue awake!\n");
@@ -7105,11 +7106,16 @@ static netdev_tx_t rtl8169_start_xmit(struct sk_buff *skb,
 
        tp->cur_tx += frags + 1;
 
-       RTL_W8(TxPoll, NPQ);
+       stop_queue = !TX_FRAGS_READY_FOR(tp, MAX_SKB_FRAGS);
 
-       mmiowb();
+       if (!skb->xmit_more || stop_queue ||
+           netif_xmit_stopped(netdev_get_tx_queue(dev, 0))) {
+               RTL_W8(TxPoll, NPQ);
+
+               mmiowb();
+       }
 
-       if (!TX_FRAGS_READY_FOR(tp, MAX_SKB_FRAGS)) {
+       if (stop_queue) {
                /* Avoid wrongly optimistic queue wake-up: rtl_tx thread must
                 * not miss a ring update when it notices a stopped queue.
                 */