1 files changed, 4 insertions, 2 deletions

diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c
index 2b75df469220..842a9c7c73a3 100644
--- a/net/dccp/ccids/ccid2.c
+++ b/net/dccp/ccids/ccid2.c
@@ -229,14 +229,16 @@ static void ccid2_cwnd_restart(struct sock *sk, const u32 now)
         struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk);
         u32 cwnd = hc->tx_cwnd, restart_cwnd,
             iwnd = rfc3390_bytes_to_packets(dccp_sk(sk)->dccps_mss_cache);
+        s32 delta = now - hc->tx_lsndtime;
 
         hc->tx_ssthresh = max(hc->tx_ssthresh, (cwnd >> 1) + (cwnd >> 2));
 
         /* don't reduce cwnd below the initial window (IW) */
         restart_cwnd = min(cwnd, iwnd);
-        cwnd >>= (now - hc->tx_lsndtime) / hc->tx_rto;
-        hc->tx_cwnd = max(cwnd, restart_cwnd);
 
+        while ((delta -= hc->tx_rto) >= 0 && cwnd > restart_cwnd)
+                cwnd >>= 1;
+        hc->tx_cwnd = max(cwnd, restart_cwnd);
         hc->tx_cwnd_stamp = now;
         hc->tx_cwnd_used  = 0;