diff --git a/include/net/tcp.h b/include/net/tcp.h
index 7ec6a28..1f57c53 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -763,10 +763,17 @@
 	CA_EVENT_CWND_RESTART,	/* congestion window restart */
 	CA_EVENT_COMPLETE_CWR,	/* end of congestion recovery */
 	CA_EVENT_LOSS,		/* loss timeout */
+	CA_EVENT_ECN_NO_CE,	/* ECT set, but not CE marked */
+	CA_EVENT_ECN_IS_CE,	/* received CE marked IP packet */
+	CA_EVENT_DELAYED_ACK,	/* Delayed ack is sent */
+	CA_EVENT_NON_DELAYED_ACK,
 };
 
+/* Information about inbound ACK, passed to cong_ops->in_ack_event() */
 enum tcp_ca_ack_event_flags {
-	CA_ACK_SLOWPATH = (1 << 0),
+	CA_ACK_SLOWPATH		= (1 << 0),	/* In slow path processing */
+	CA_ACK_WIN_UPDATE	= (1 << 1),	/* ACK updated window */
+	CA_ACK_ECE		= (1 << 2),	/* ECE bit is set on ack */
 };
 
 /*
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 8a38774..fc13317 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -233,14 +233,21 @@
 			tcp_enter_quickack_mode((struct sock *)tp);
 		break;
 	case INET_ECN_CE:
+		if (tcp_ca_needs_ecn((struct sock *)tp))
+			tcp_ca_event((struct sock *)tp, CA_EVENT_ECN_IS_CE);
+
 		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;
+		break;
+	default:
+		if (tcp_ca_needs_ecn((struct sock *)tp))
+			tcp_ca_event((struct sock *)tp, CA_EVENT_ECN_NO_CE);
+		tp->ecn_flags |= TCP_ECN_SEEN;
+		break;
 	}
 }
 
@@ -3429,10 +3436,12 @@
 		tp->snd_una = ack;
 		flag |= FLAG_WIN_UPDATE;
 
-		tcp_in_ack_event(sk, 0);
+		tcp_in_ack_event(sk, CA_ACK_WIN_UPDATE);
 
 		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPHPACKS);
 	} else {
+		u32 ack_ev_flags = CA_ACK_SLOWPATH;
+
 		if (ack_seq != TCP_SKB_CB(skb)->end_seq)
 			flag |= FLAG_DATA;
 		else
@@ -3444,10 +3453,15 @@
 			flag |= tcp_sacktag_write_queue(sk, skb, prior_snd_una,
 							&sack_rtt_us);
 
-		if (TCP_ECN_rcv_ecn_echo(tp, tcp_hdr(skb)))
+		if (TCP_ECN_rcv_ecn_echo(tp, tcp_hdr(skb))) {
 			flag |= FLAG_ECE;
+			ack_ev_flags |= CA_ACK_ECE;
+		}
 
-		tcp_in_ack_event(sk, CA_ACK_SLOWPATH);
+		if (flag & FLAG_WIN_UPDATE)
+			ack_ev_flags |= CA_ACK_WIN_UPDATE;
+
+		tcp_in_ack_event(sk, ack_ev_flags);
 	}
 
 	/* We passed data and got it acked, remove any soft error
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 20e7327..124f9e4 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -3130,6 +3130,8 @@
 	int ato = icsk->icsk_ack.ato;
 	unsigned long timeout;
 
+	tcp_ca_event(sk, CA_EVENT_DELAYED_ACK);
+
 	if (ato > TCP_DELACK_MIN) {
 		const struct tcp_sock *tp = tcp_sk(sk);
 		int max_ato = HZ / 2;
@@ -3186,6 +3188,8 @@
 	if (sk->sk_state == TCP_CLOSE)
 		return;
 
+	tcp_ca_event(sk, CA_EVENT_NON_DELAYED_ACK);
+
 	/* We are not putting this on the write queue, so
 	 * tcp_transmit_skb() will set the ownership to this
 	 * sock.