diff --git a/src/runtime/src/rtio_mgt.rs b/src/runtime/src/rtio_mgt.rs
index b6c1d2b..ee8d79c 100644
--- a/src/runtime/src/rtio_mgt.rs
+++ b/src/runtime/src/rtio_mgt.rs
@@ -45,7 +45,7 @@ pub mod drtio {
         unsafe { (csr::DRTIO[linkno].rx_up_read)() == 1 }
     }
 
-    async fn process_async_packets(linkno: u8, packet: Packet) -> Option<Packet> {
+    async fn process_async_packets(aux_mutex: &Mutex<bool>, linkno: u8, packet: Packet) -> Option<Packet> {
         // returns None if an async packet has been consumed
         match packet {
             Packet::DmaPlaybackStatus {
@@ -71,6 +71,7 @@ pub mod drtio {
             } => {
                 subkernel::message_handle_incoming(id, last, length as usize, &data).await;
                 // acknowledge receiving part of the message
+                let _lock = aux_mutex.async_lock().await;
                 drtioaux_async::send(linkno, &Packet::SubkernelMessageAck { destination: from })
                     .await
                     .unwrap();
@@ -102,14 +103,7 @@ pub mod drtio {
         }
         let _lock = aux_mutex.async_lock().await;
         drtioaux_async::send(linkno, request).await.unwrap();
-        loop {
-            let reply = recv_aux_timeout(linkno, 200, timer).await?;
-            let packet = process_async_packets(linkno, reply).await;
-            match packet {
-                Some(packet) => return Ok(packet),
-                None => (),
-            }
-        }
+        Ok(recv_aux_timeout(linkno, 200, timer).await?)
     }
 
     async fn drain_buffer(linkno: u8, draining_time: Milliseconds, timer: GlobalTimer) {
@@ -219,7 +213,7 @@ pub mod drtio {
         let _lock = aux_mutex.async_lock().await;
         match drtioaux_async::recv(linkno).await {
             Ok(Some(packet)) => {
-                if let Some(packet) = process_async_packets(linkno, packet).await {
+                if let Some(packet) = process_async_packets(aux_mutex, linkno, packet).await {
                     warn!("[LINK#{}] unsolicited aux packet: {:?}", linkno, packet);
                 }
             }
@@ -291,53 +285,61 @@ pub mod drtio {
                 let linkno = hop - 1;
                 if destination_up(up_destinations, destination).await {
                     if up_links[linkno as usize] {
-                        let reply = aux_transact(
-                            aux_mutex,
-                            linkno,
-                            &Packet::DestinationStatusRequest {
-                                destination: destination,
-                            },
-                            timer,
-                        )
-                        .await;
-                        match reply {
-                            Ok(Packet::DestinationDownReply) => {
-                                destination_set_up(routing_table, up_destinations, destination, false).await;
-                                remote_dma::destination_changed(aux_mutex, routing_table, timer, destination, false)
-                                    .await;
-                                subkernel::destination_changed(aux_mutex, routing_table, timer, destination, false)
-                                    .await;
+                        loop {
+                            let reply = aux_transact(
+                                aux_mutex,
+                                linkno,
+                                &Packet::DestinationStatusRequest {
+                                    destination: destination,
+                                },
+                                timer,
+                            )
+                            .await;
+                            match reply {
+                                Ok(Packet::DestinationDownReply) => {
+                                    destination_set_up(routing_table, up_destinations, destination, false).await;
+                                    remote_dma::destination_changed(aux_mutex, routing_table, timer, destination, false)
+                                        .await;
+                                    subkernel::destination_changed(aux_mutex, routing_table, timer, destination, false)
+                                        .await;
+                                }
+                                Ok(Packet::DestinationOkReply) => (),
+                                Ok(Packet::DestinationSequenceErrorReply { channel }) => {
+                                    error!(
+                                        "[DEST#{}] RTIO sequence error involving channel 0x{:04x}:{}",
+                                        destination,
+                                        channel,
+                                        resolve_channel_name(channel as u32)
+                                    );
+                                    unsafe { SEEN_ASYNC_ERRORS |= ASYNC_ERROR_SEQUENCE_ERROR };
+                                }
+                                Ok(Packet::DestinationCollisionReply { channel }) => {
+                                    error!(
+                                        "[DEST#{}] RTIO collision involving channel 0x{:04x}:{}",
+                                        destination,
+                                        channel,
+                                        resolve_channel_name(channel as u32)
+                                    );
+                                    unsafe { SEEN_ASYNC_ERRORS |= ASYNC_ERROR_COLLISION };
+                                }
+                                Ok(Packet::DestinationBusyReply { channel }) => {
+                                    error!(
+                                        "[DEST#{}] RTIO busy error involving channel 0x{:04x}:{}",
+                                        destination,
+                                        channel,
+                                        resolve_channel_name(channel as u32)
+                                    );
+                                    unsafe { SEEN_ASYNC_ERRORS |= ASYNC_ERROR_BUSY };
+                                }
+                                Ok(packet) => {
+                                    match process_async_packets(aux_mutex, linkno, packet).await {
+                                        Some(packet) => error!("[DEST#{}] received unexpected aux packet: {:?}", destination, packet),
+                                        None => continue
+                                    }
+                                },
+                                Err(e) => error!("[DEST#{}] communication failed ({})", destination, e),
                             }
-                            Ok(Packet::DestinationOkReply) => (),
-                            Ok(Packet::DestinationSequenceErrorReply { channel }) => {
-                                error!(
-                                    "[DEST#{}] RTIO sequence error involving channel 0x{:04x}:{}",
-                                    destination,
-                                    channel,
-                                    resolve_channel_name(channel as u32)
-                                );
-                                unsafe { SEEN_ASYNC_ERRORS |= ASYNC_ERROR_SEQUENCE_ERROR };
-                            }
-                            Ok(Packet::DestinationCollisionReply { channel }) => {
-                                error!(
-                                    "[DEST#{}] RTIO collision involving channel 0x{:04x}:{}",
-                                    destination,
-                                    channel,
-                                    resolve_channel_name(channel as u32)
-                                );
-                                unsafe { SEEN_ASYNC_ERRORS |= ASYNC_ERROR_COLLISION };
-                            }
-                            Ok(Packet::DestinationBusyReply { channel }) => {
-                                error!(
-                                    "[DEST#{}] RTIO busy error involving channel 0x{:04x}:{}",
-                                    destination,
-                                    channel,
-                                    resolve_channel_name(channel as u32)
-                                );
-                                unsafe { SEEN_ASYNC_ERRORS |= ASYNC_ERROR_BUSY };
-                            }
-                            Ok(packet) => error!("[DEST#{}] received unexpected aux packet: {:?}", destination, packet),
-                            Err(e) => error!("[DEST#{}] communication failed ({})", destination, e),
+                            break;
                         }
                     } else {
                         destination_set_up(routing_table, up_destinations, destination, false).await;