bbr2_prior_cwnd.patch

commit 9ed0fd60880a7359db62605f6f8a578f621e6326
Author: Alexey Ivanov <rbtz@dropbox.com>
Date:   Sat Oct 12 16:55:05 2019 +0000

    [DBX] net-tcp_bbr: v2: disable spurious warning

    This warning is due to the fact that tcp_simple_retransmit() calls

    tcp_set_ca_state(sk, TCP_CA_Loss);

    without first calling icsk_ca_ops->ssthresh(sk) (because
    tcp_simple_retransmit() is dealing with losses due to MTU issues and not
    congestion).

diff --git a/net/ipv4/tcp_bbr2.c b/net/ipv4/tcp_bbr2.c
index c83665742436..9a2ce5b9fbdf 100644
--- a/net/ipv4/tcp_bbr2.c
+++ b/net/ipv4/tcp_bbr2.c
@@ -2424,7 +2424,6 @@ static void bbr_set_state(struct sock *sk, u8 new_state)
                bbr_debug(sk, 0, &rs, &dbg);
        } else if (bbr->prev_ca_state == TCP_CA_Loss &&
                   new_state != TCP_CA_Loss) {
-               WARN_ON_ONCE(bbr->prior_cwnd == 0);
                WARN_ON_ONCE(bbr->prior_cwnd == ~0U);
                tp->snd_cwnd = max(tp->snd_cwnd, bbr->prior_cwnd);
        }