changed send receive thread to add peer and remove peer

network_device/flxnet/flxnet.h

@@ -16,7 +16,6 @@ struct flxnet_peer {
 	unsigned int reg_recv;
 	unsigned int reg_status;
 	unsigned char mac_addr[ETH_ALEN];
-	unsigned int role;
 	struct net_device *flxnet;
 	struct tx_queue tx_queue;
 };

network_device/flxnet_dev.c

@@ -226,6 +226,15 @@ void flxnet_remove_peer(struct flxnet_peer *peer) {
 	list_del(&peer->peer_entry);
 	kfree(peer);
 	mutex_unlock(&peer_mutex);
+
+	if (list_empty(&peer_list)) {
+		// disable RX side when all peers are removed
+		if (message_level & NETIF_MSG_IFDOWN)
+			pr_info("flxnet_dev: stop RX thread\n");	
+		wake_up_interruptible(&recv_queue);
+		kthread_stop(recv_task);
+		del_timer_sync(&recv_timer);
+	}
 }
 
 static bool tx_queue_is_full(struct flxnet_peer *peer) {
@@ -971,6 +980,19 @@ struct flxnet_peer * flxnet_add_peer(void* __iomem base_address) {
 	struct flxnet_peer *peer;
 	pr_info("flxnet_dev: flxnet_add_peer %lX\n", (long unsigned int)base_address);
 
+	if (list_empty(&peer_list)) {
+		// enable RX side when the first peer is added
+		if (message_level & NETIF_MSG_IFUP)
+			pr_info("flxnet_dev: initialize RX thread and timer\n");
+		recv_task = kthread_create(send_recv_thread, NULL, "flxnet RX thread");
+		if (IS_ERR(recv_task)) {
+			pr_err("flxnet_dev: failed to create RX thread in %s\n", __FUNCTION__);
+			return -1;
+		}
+		wake_up_process(recv_task);
+		mod_timer(&recv_timer, jiffies + msecs_to_jiffies(POLL_PERIOD_MS));
+	}
+
 	mutex_lock(&peer_mutex);
 	peer = kzalloc(sizeof(struct flxnet_peer), GFP_KERNEL);
 	if (IS_ERR(peer)) {
@@ -1015,32 +1037,12 @@ int __init flxnet_dev_init(void) {
 	init_waitqueue_head(&recv_queue);
 	timer_setup(&recv_timer, recv_timer_function, 0);
 	INIT_LIST_HEAD(&peer_list);
-
-	// enable RX side
-	if (message_level & NETIF_MSG_IFUP)
-		pr_info("flxnet_dev: initialize RX thread and timer\n");
-	recv_task = kthread_create(send_recv_thread, NULL, "flxnet RX thread");
-	if (IS_ERR(recv_task)) {
-		pr_err("flxnet_dev: failed to create RX thread in %s\n", __FUNCTION__);
-		return -1;
-	}
-
-	wake_up_process(recv_task);
-	mod_timer(&recv_timer, jiffies + msecs_to_jiffies(POLL_PERIOD_MS));
-
 	return 0;
 }
 
 void __exit flxnet_dev_exit(void) {	
 	pr_info("flxnet_dev: removing %s driver\n", DRV_NAME);
 
-	// disable RX side	
-	if (message_level & NETIF_MSG_IFDOWN)
-		pr_info("flxnet_dev: stop RX thread\n");	
-	wake_up_interruptible(&recv_queue);
-	kthread_stop(recv_task);
-	del_timer_sync(&recv_timer);
-
 	mutex_destroy(&peer_mutex);
 	mutex_destroy(&flxnet_mutex);
 }