diff --git a/Documentation/networking/dccp.txt b/Documentation/networking/dccp.txt
index b395ca6a49f296e7b1ddda4e6a580f8691b22532..811872b45beee140a7d1a561b9cee9eadf211b48 100644
--- a/Documentation/networking/dccp.txt
+++ b/Documentation/networking/dccp.txt
@@ -167,6 +167,7 @@ rx_ccid = 2
 seq_window = 100
 	The initial sequence window (sec. 7.5.2) of the sender. This influences
 	the local ackno validity and the remote seqno validity windows (7.5.1).
+	Values in the range Wmin = 32 (RFC 4340, 7.5.2) up to 2^32-1 can be set.
 
 tx_qlen = 5
 	The size of the transmit buffer in packets. A value of 0 corresponds
diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h
index 45087052d8948b3fcdb8808e990217b227c5aba9..5fdb072290178a2a7b1d4b9b64fb80cbe02a465e 100644
--- a/net/dccp/dccp.h
+++ b/net/dccp/dccp.h
@@ -426,7 +426,8 @@ static inline void dccp_update_gsr(struct sock *sk, u64 seq)
 {
 	struct dccp_sock *dp = dccp_sk(sk);
 
-	dp->dccps_gsr = seq;
+	if (after48(seq, dp->dccps_gsr))
+		dp->dccps_gsr = seq;
 	/* Sequence validity window depends on remote Sequence Window (7.5.1) */
 	dp->dccps_swl = SUB48(ADD48(dp->dccps_gsr, 1), dp->dccps_r_seq_win / 4);
 	/*
diff --git a/net/dccp/input.c b/net/dccp/input.c
index 15af247ea007a9e77f484a21c3cfe10d6796ff16..8cde009e8b8501ead8ff3e94ef6bfbaabc33088c 100644
--- a/net/dccp/input.c
+++ b/net/dccp/input.c
@@ -260,7 +260,7 @@ static int dccp_check_seqno(struct sock *sk, struct sk_buff *skb)
 		 */
 		if (time_before(now, (dp->dccps_rate_last +
 				      sysctl_dccp_sync_ratelimit)))
-			return 0;
+			return -1;
 
 		DCCP_WARN("Step 6 failed for %s packet, "
 			  "(LSWL(%llu) <= P.seqno(%llu) <= S.SWH(%llu)) and "
diff --git a/net/dccp/sysctl.c b/net/dccp/sysctl.c
index 563943822e58287412217e3e13963a507cdeff3b..42348824ee318c31f4a3ae901d1d5e57aa1f8c17 100644
--- a/net/dccp/sysctl.c
+++ b/net/dccp/sysctl.c
@@ -21,7 +21,8 @@
 /* Boundary values */
 static int		zero     = 0,
 			u8_max   = 0xFF;
-static unsigned long	seqw_min = 32;
+static unsigned long	seqw_min = DCCPF_SEQ_WMIN,
+			seqw_max = 0xFFFFFFFF;		/* maximum on 32 bit */
 
 static struct ctl_table dccp_default_table[] = {
 	{
@@ -31,6 +32,7 @@ static struct ctl_table dccp_default_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_doulongvec_minmax,
 		.extra1		= &seqw_min,		/* RFC 4340, 7.5.2 */
+		.extra2		= &seqw_max,
 	},
 	{
 		.procname	= "rx_ccid",