tcp: do not cancel delay-AcK on DCTCP special ACK

[linux-2.6-microblaze.git] / net / ipv4 / tcp_dctcp.c

diff --git a/net/ipv4/tcp_dctcp.c b/net/ipv4/tcp_dctcp.c
index 5f5e593..078328a 100644 (file)
--- a/net/ipv4/tcp_dctcp.c
+++ b/net/ipv4/tcp_dctcp.c
@@ -55,7 +55,6 @@ struct dctcp {
        u32 dctcp_alpha;
        u32 next_seq;
        u32 ce_state;
-       u32 delayed_ack_reserved;
        u32 loss_cwnd;
 };
 
@@ -96,7 +95,6 @@ static void dctcp_init(struct sock *sk)
 
                ca->dctcp_alpha = min(dctcp_alpha_on_init, DCTCP_MAX_ALPHA);
 
-               ca->delayed_ack_reserved = 0;
                ca->loss_cwnd = 0;
                ca->ce_state = 0;
 
@@ -134,21 +132,9 @@ static void dctcp_ce_state_0_to_1(struct sock *sk)
        /* State has changed from CE=0 to CE=1 and delayed
         * ACK has not sent yet.
         */
-       if (!ca->ce_state && ca->delayed_ack_reserved) {
-               u32 tmp_rcv_nxt;
-
-               /* Save current rcv_nxt. */
-               tmp_rcv_nxt = tp->rcv_nxt;
-
-               /* Generate previous ack with CE=0. */
-               tp->ecn_flags &= ~TCP_ECN_DEMAND_CWR;
-               tp->rcv_nxt = ca->prior_rcv_nxt;
-
-               tcp_send_ack(sk);
-
-               /* Recover current rcv_nxt. */
-               tp->rcv_nxt = tmp_rcv_nxt;
-       }
+       if (!ca->ce_state &&
+           inet_csk(sk)->icsk_ack.pending & ICSK_ACK_TIMER)
+               __tcp_send_ack(sk, ca->prior_rcv_nxt);
 
        ca->prior_rcv_nxt = tp->rcv_nxt;
        ca->ce_state = 1;
@@ -164,21 +150,9 @@ static void dctcp_ce_state_1_to_0(struct sock *sk)
        /* State has changed from CE=1 to CE=0 and delayed
         * ACK has not sent yet.
         */
-       if (ca->ce_state && ca->delayed_ack_reserved) {
-               u32 tmp_rcv_nxt;
-
-               /* Save current rcv_nxt. */
-               tmp_rcv_nxt = tp->rcv_nxt;
-
-               /* Generate previous ack with CE=1. */
-               tp->ecn_flags |= TCP_ECN_DEMAND_CWR;
-               tp->rcv_nxt = ca->prior_rcv_nxt;
-
-               tcp_send_ack(sk);
-
-               /* Recover current rcv_nxt. */
-               tp->rcv_nxt = tmp_rcv_nxt;
-       }
+       if (ca->ce_state &&
+           inet_csk(sk)->icsk_ack.pending & ICSK_ACK_TIMER)
+               __tcp_send_ack(sk, ca->prior_rcv_nxt);
 
        ca->prior_rcv_nxt = tp->rcv_nxt;
        ca->ce_state = 0;
@@ -248,25 +222,6 @@ static void dctcp_state(struct sock *sk, u8 new_state)
        }
 }
 
-static void dctcp_update_ack_reserved(struct sock *sk, enum tcp_ca_event ev)
-{
-       struct dctcp *ca = inet_csk_ca(sk);
-
-       switch (ev) {
-       case CA_EVENT_DELAYED_ACK:
-               if (!ca->delayed_ack_reserved)
-                       ca->delayed_ack_reserved = 1;
-               break;
-       case CA_EVENT_NON_DELAYED_ACK:
-               if (ca->delayed_ack_reserved)
-                       ca->delayed_ack_reserved = 0;
-               break;
-       default:
-               /* Don't care for the rest. */
-               break;
-       }
-}
-
 static void dctcp_cwnd_event(struct sock *sk, enum tcp_ca_event ev)
 {
        switch (ev) {
@@ -276,10 +231,6 @@ static void dctcp_cwnd_event(struct sock *sk, enum tcp_ca_event ev)
        case CA_EVENT_ECN_NO_CE:
                dctcp_ce_state_1_to_0(sk);
                break;
-       case CA_EVENT_DELAYED_ACK:
-       case CA_EVENT_NON_DELAYED_ACK:
-               dctcp_update_ack_reserved(sk, ev);
-               break;
        default:
                /* Don't care for the rest. */
                break;