diff --git a/platform/embedded/btstack_run_loop_embedded.c b/platform/embedded/btstack_run_loop_embedded.c
index 752473a6f..67c4750aa 100644
--- a/platform/embedded/btstack_run_loop_embedded.c
+++ b/platform/embedded/btstack_run_loop_embedded.c
@@ -172,7 +172,7 @@ void btstack_run_loop_embedded_execute_once(void) {
     btstack_data_source_t *next;
     for (ds = (btstack_data_source_t *) data_sources; ds != NULL ; ds = next){
         next = (btstack_data_source_t *) ds->item.next; // cache pointer to next data_source to allow data source to remove itself
-        ds->process(ds);
+        ds->process(ds, DATA_SOURCE_CALLBACK_POLL);
     }
     
 #ifdef HAVE_TICK
@@ -187,7 +187,7 @@ void btstack_run_loop_embedded_execute_once(void) {
         btstack_timer_source_t *ts = (btstack_timer_source_t *) timers;
         if (ts->timeout > now) break;
         btstack_run_loop_remove_timer(ts);
-        ts->process(ts, DATA_SOURCE_CALLBACK_POLL);
+        ts->process(ts);
     }
 #endif
     
diff --git a/port/libusb/hci_transport_h2_libusb.c b/port/libusb/hci_transport_h2_libusb.c
index d5bf285ff..043c5a077 100644
--- a/port/libusb/hci_transport_h2_libusb.c
+++ b/port/libusb/hci_transport_h2_libusb.c
@@ -401,7 +401,7 @@ static void handle_completed_transfer(struct libusb_transfer *transfer){
 }
 
 static void usb_process_ds(btstack_data_source_t *ds, btstack_data_source_callback_type_t callback_type) {
-    if (libusb_state != LIB_USB_TRANSFERS_ALLOCATED) return -1;
+    if (libusb_state != LIB_USB_TRANSFERS_ALLOCATED) return;
 
     // log_info("begin usb_process_ds");
     // always handling an event as we're called when data is ready
@@ -415,7 +415,7 @@ static void usb_process_ds(btstack_data_source_t *ds, btstack_data_source_callba
         void * next = handle_packet->user_data;
         handle_completed_transfer(handle_packet);
         // handle case where libusb_close might be called by hci packet handler        
-        if (libusb_state != LIB_USB_TRANSFERS_ALLOCATED) return -1;
+        if (libusb_state != LIB_USB_TRANSFERS_ALLOCATED) return;
 
         // Move to next in the list of packets to handle
         if (next) {
@@ -425,7 +425,6 @@ static void usb_process_ds(btstack_data_source_t *ds, btstack_data_source_callba
         }
     }
     // log_info("end usb_process_ds");
-    return 0;
 }
 
 static void usb_process_ts(btstack_timer_source_t *timer) {
@@ -437,7 +436,7 @@ static void usb_process_ts(btstack_timer_source_t *timer) {
     if (libusb_state != LIB_USB_TRANSFERS_ALLOCATED) return;
 
     // actually handled the packet in the pollfds function
-    usb_process_ds((struct btstack_data_source *) NULL);
+    usb_process_ds((struct btstack_data_source *) NULL, DATA_SOURCE_CALLBACK_READ);
 
     // Get the amount of time until next event is due
     long msec = AYSNC_POLLING_INTERVAL_MS;