From caa5d73974eab7db2beafb0decefa3f9f7e0e396 Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@google.com>
Date: Mon, 6 Aug 2012 11:04:43 +0000
Subject: [PATCH] --- yaml --- r: 327388 b: refs/heads/master c:
 aae06bf5f90403554f8d4ff83810a8281aef7f03 h: refs/heads/master v: v3

---
 [refs]                     | 2 +-
 trunk/net/ipv4/tcp_input.c | 6 +++++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index 18ac201b6edc..907f7f778345 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: a9e050f4e7f9d36afe0dcc0bddba864ee442715e
+refs/heads/master: aae06bf5f90403554f8d4ff83810a8281aef7f03
diff --git a/trunk/net/ipv4/tcp_input.c b/trunk/net/ipv4/tcp_input.c
index 2fd2bc9e3c64..fa2c2c2cac2d 100644
--- a/trunk/net/ipv4/tcp_input.c
+++ b/trunk/net/ipv4/tcp_input.c
@@ -237,7 +237,11 @@ static inline void TCP_ECN_check_ce(struct tcp_sock *tp, const struct sk_buff *s
 			tcp_enter_quickack_mode((struct sock *)tp);
 		break;
 	case INET_ECN_CE:
-		tp->ecn_flags |= TCP_ECN_DEMAND_CWR;
+		if (!(tp->ecn_flags & TCP_ECN_DEMAND_CWR)) {
+			/* Better not delay acks, sender can have a very low cwnd */
+			tcp_enter_quickack_mode((struct sock *)tp);
+			tp->ecn_flags |= TCP_ECN_DEMAND_CWR;
+		}
 		/* fallinto */
 	default:
 		tp->ecn_flags |= TCP_ECN_SEEN;