diff --git a/include/trace/events/rxrpc.h b/include/trace/events/rxrpc.h
index 059b6e45a028..839bb07b93a7 100644
--- a/include/trace/events/rxrpc.h
+++ b/include/trace/events/rxrpc.h
@@ -1511,7 +1511,7 @@ TRACE_EVENT(rxrpc_call_reset,
 		    __entry->call_serial = call->rx_serial;
 		    __entry->conn_serial = call->conn->hi_serial;
 		    __entry->tx_seq = call->tx_hard_ack;
-		    __entry->rx_seq = call->ackr_seen;
+		    __entry->rx_seq = call->rx_hard_ack;
 			   ),
 
 	    TP_printk("c=%08x %08x:%08x r=%08x/%08x tx=%08x rx=%08x",
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 8ca7afe0ac26..cb174f699665 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -669,8 +669,8 @@ struct rxrpc_call {
 	u8			ackr_reason;	/* reason to ACK */
 	rxrpc_serial_t		ackr_serial;	/* serial of packet being ACK'd */
 	rxrpc_seq_t		ackr_highest_seq; /* Higest sequence number received */
-	rxrpc_seq_t		ackr_consumed;	/* Highest packet shown consumed */
-	rxrpc_seq_t		ackr_seen;	/* Highest packet shown seen */
+	atomic_t		ackr_nr_unacked; /* Number of unacked packets */
+	atomic_t		ackr_nr_consumed; /* Number of packets needing hard ACK */
 
 	/* ping management */
 	rxrpc_serial_t		ping_serial;	/* Last ping sent */
diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index 8eafa3463b88..5cf64cf8debf 100644
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -413,8 +413,8 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
 {
 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 	enum rxrpc_call_state state;
-	unsigned int j, nr_subpackets;
-	rxrpc_serial_t serial = sp->hdr.serial, ack_serial = 0;
+	unsigned int j, nr_subpackets, nr_unacked = 0;
+	rxrpc_serial_t serial = sp->hdr.serial, ack_serial = serial;
 	rxrpc_seq_t seq0 = sp->hdr.seq, hard_ack;
 	bool immediate_ack = false, jumbo_bad = false;
 	u8 ack = 0;
@@ -570,6 +570,8 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
 			sp = NULL;
 		}
 
+		nr_unacked++;
+
 		if (last) {
 			set_bit(RXRPC_CALL_RX_LAST, &call->flags);
 			if (!ack) {
@@ -589,9 +591,14 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
 			}
 			call->rx_expect_next = seq + 1;
 		}
+		if (!ack)
+			ack_serial = serial;
 	}
 
 ack:
+	if (atomic_add_return(nr_unacked, &call->ackr_nr_unacked) > 2 && !ack)
+		ack = RXRPC_ACK_IDLE;
+
 	if (ack)
 		rxrpc_propose_ACK(call, ack, ack_serial,
 				  immediate_ack, true,
diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c
index 7f1c8116e030..6202d2e32914 100644
--- a/net/rxrpc/output.c
+++ b/net/rxrpc/output.c
@@ -74,11 +74,18 @@ static size_t rxrpc_fill_out_ack(struct rxrpc_connection *conn,
 				 u8 reason)
 {
 	rxrpc_serial_t serial;
+	unsigned int tmp;
 	rxrpc_seq_t hard_ack, top, seq;
 	int ix;
 	u32 mtu, jmax;
 	u8 *ackp = pkt->acks;
 
+	tmp = atomic_xchg(&call->ackr_nr_unacked, 0);
+	tmp |= atomic_xchg(&call->ackr_nr_consumed, 0);
+	if (!tmp && (reason == RXRPC_ACK_DELAY ||
+		     reason == RXRPC_ACK_IDLE))
+		return 0;
+
 	/* Barrier against rxrpc_input_data(). */
 	serial = call->ackr_serial;
 	hard_ack = READ_ONCE(call->rx_hard_ack);
@@ -180,6 +187,10 @@ int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping,
 	n = rxrpc_fill_out_ack(conn, call, pkt, &hard_ack, &top, reason);
 
 	spin_unlock_bh(&call->lock);
+	if (n == 0) {
+		kfree(pkt);
+		return 0;
+	}
 
 	iov[0].iov_base	= pkt;
 	iov[0].iov_len	= sizeof(pkt->whdr) + sizeof(pkt->ack) + n;
@@ -227,13 +238,6 @@ int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping,
 					  ntohl(pkt->ack.serial),
 					  false, true,
 					  rxrpc_propose_ack_retry_tx);
-		} else {
-			spin_lock_bh(&call->lock);
-			if (after(hard_ack, call->ackr_consumed))
-				call->ackr_consumed = hard_ack;
-			if (after(top, call->ackr_seen))
-				call->ackr_seen = top;
-			spin_unlock_bh(&call->lock);
 		}
 
 		rxrpc_set_keepalive(call);
diff --git a/net/rxrpc/recvmsg.c b/net/rxrpc/recvmsg.c
index 4f48e3bdd4b4..c75789ebc514 100644
--- a/net/rxrpc/recvmsg.c
+++ b/net/rxrpc/recvmsg.c
@@ -212,11 +212,9 @@ static void rxrpc_rotate_rx_window(struct rxrpc_call *call)
 		rxrpc_end_rx_phase(call, serial);
 	} else {
 		/* Check to see if there's an ACK that needs sending. */
-		if (after_eq(hard_ack, call->ackr_consumed + 2) ||
-		    after_eq(top, call->ackr_seen + 2) ||
-		    (hard_ack == top && after(hard_ack, call->ackr_consumed)))
-			rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, serial,
-					  true, true,
+		if (atomic_inc_return(&call->ackr_nr_consumed) > 2)
+			rxrpc_propose_ACK(call, RXRPC_ACK_IDLE, serial,
+					  true, false,
 					  rxrpc_propose_ack_rotate_rx);
 		if (call->ackr_reason && call->ackr_reason != RXRPC_ACK_DELAY)
 			rxrpc_send_ack_packet(call, false, NULL);