diff --git a/src/modules/module-client-node/client-node.c b/src/modules/module-client-node/client-node.c
index 255cbbca6..2c4d4ad21 100644
--- a/src/modules/module-client-node/client-node.c
+++ b/src/modules/module-client-node/client-node.c
@@ -47,6 +47,7 @@
 
 #define MAX_BUFFERS	64
 #define MAX_AREAS	1024
+#define MAX_IO		16
 
 #define CHECK_IN_PORT_ID(this,d,p)       ((d) == SPA_DIRECTION_INPUT && (p) < MAX_INPUTS)
 #define CHECK_OUT_PORT_ID(this,d,p)      ((d) == SPA_DIRECTION_OUTPUT && (p) < MAX_OUTPUTS)
@@ -81,6 +82,11 @@ struct buffer {
 	uint32_t memid;
 };
 
+struct io {
+	uint32_t id;
+	uint32_t memid;
+};
+
 struct port {
 	bool valid;
 	struct spa_port_info info;
@@ -89,10 +95,11 @@ struct port {
 	bool have_format;
 	uint32_t n_params;
 	struct spa_pod **params;
-	struct spa_io_buffers *io;
 
 	uint32_t n_buffers;
 	struct buffer buffers[MAX_BUFFERS];
+
+	struct io ios[MAX_IO];
 };
 
 struct node {
@@ -139,7 +146,6 @@ struct impl {
 
 	struct pw_map io_map;
 	struct pw_memblock *io_areas;
-	uint32_t io_memid;
 
 	struct spa_hook node_listener;
 	struct spa_hook resource_listener;
@@ -185,6 +191,53 @@ static struct mem *ensure_mem(struct impl *impl, int fd, uint32_t type, uint32_t
 	return m;
 }
 
+static void clear_io(struct node *node, struct io *io)
+{
+	struct mem *m;
+	m = pw_array_get_unchecked(&node->impl->mems, io->memid, struct mem);
+	m->ref--;
+	io->id = SPA_ID_INVALID;
+}
+
+static struct io *update_io(struct impl *impl, struct port *port, uint32_t id, uint32_t memid)
+{
+	int i;
+	struct io *io, *f = NULL;
+
+	for (i = 0; i < MAX_IO; i++) {
+		io = &port->ios[i];
+		if (io->id == SPA_ID_INVALID)
+			f = io;
+		else if (io->id == id) {
+			if (io->memid != memid) {
+				clear_io(&impl->node, io);
+				if (memid == SPA_ID_INVALID)
+					io->id = SPA_ID_INVALID;
+			}
+			goto found;
+		}
+	}
+	if (f == NULL)
+		return NULL;
+
+	io = f;
+	io->id = id;
+	io->memid = memid;
+
+     found:
+	return io;
+}
+
+static void clear_ios(struct node *this, struct port *port)
+{
+	int i;
+
+	for (i = 0; i < MAX_IO; i++) {
+		struct io *io = &port->ios[i];
+		if (io->id != SPA_ID_INVALID)
+			clear_io(this, io);
+	}
+}
 
 static int clear_buffers(struct node *this, struct port *port)
 {
@@ -266,12 +319,12 @@ static int impl_node_set_param(struct spa_node *node, uint32_t id, uint32_t flag
 	return SPA_RESULT_RETURN_ASYNC(this->seq++);
 }
 
-static inline void do_flush(struct node *this)
+static inline void send_process(struct node *this)
 {
 	uint64_t cmd = 1;
+	pw_log_trace("client-node %p: send process", this);
 	if (write(this->writefd, &cmd, 8) != 8)
-		spa_log_warn(this->log, "node %p: error flushing : %s", this, strerror(errno));
-
+		spa_log_warn(this->log, "node %p: error %s", this, strerror(errno));
 }
 
 static int impl_node_send_command(struct spa_node *node, const struct spa_command *command)
@@ -384,12 +437,11 @@ do_update_port(struct node *this,
 {
 	struct port *port;
 	struct pw_type *t = this->impl->t;
+	int i;
 
 	port = GET_PORT(this, direction, port_id);
 
 	if (change_mask & PW_CLIENT_NODE_PORT_UPDATE_PARAMS) {
-		int i;
-
 		port->have_format = false;
 
 		spa_log_info(this->log, "node %p: port %u update %d params", this, port_id, n_params);
@@ -425,6 +477,8 @@ do_update_port(struct node *this,
 		spa_log_info(this->log, "node %p: adding port %d", this, port_id);
 		port->have_format = false;
 		port->valid = true;
+		for (i = 0; i < MAX_IO; i++)
+			port->ios[i].id = SPA_ID_INVALID;
 
 		if (direction == SPA_DIRECTION_INPUT)
 			this->n_inputs++;
@@ -443,6 +497,7 @@ clear_port(struct node *this,
 		       PW_CLIENT_NODE_PORT_UPDATE_PARAMS |
 		       PW_CLIENT_NODE_PORT_UPDATE_INFO, 0, NULL, NULL);
 	clear_buffers(this, port);
+	clear_ios(this, port);
 }
 
 static void do_uninit_port(struct node *this, enum spa_direction direction, uint32_t port_id)
@@ -597,6 +652,7 @@ static int do_port_set_io(struct impl *impl,
 	struct pw_memblock *mem;
 	struct mem *m;
 	uint32_t memid, mem_offset, mem_size;
+	struct port *port;
 
 	pw_log_debug("client-node %p: %s port %d.%d set io %p %zd", impl,
 			direction == SPA_DIRECTION_INPUT ? "input" : "output",
@@ -608,6 +664,8 @@ static int do_port_set_io(struct impl *impl,
 	if (this->resource == NULL)
 		return 0;
 
+	port = GET_PORT(this, direction, port_id);
+
 	if (data) {
 		if ((mem = pw_memblock_find(data)) == NULL)
 			return -EINVAL;
@@ -625,6 +683,7 @@ static int do_port_set_io(struct impl *impl,
 		memid = SPA_ID_INVALID;
 		mem_offset = mem_size = 0;
 	}
+	update_io(impl, port, id, memid);
 
 	pw_client_node_resource_port_set_io(this->resource,
 					    this->seq,
@@ -805,7 +864,7 @@ impl_node_port_reuse_buffer(struct spa_node *node, uint32_t port_id, uint32_t bu
 
 	pw_client_node_transport_add_message(impl->transport, (struct pw_client_node_message *)
 			&PW_CLIENT_NODE_MESSAGE_PORT_REUSE_BUFFER_INIT(port_id, buffer_id));
-	do_flush(this);
+	send_process(this);
 
 	return 0;
 }
@@ -842,14 +901,14 @@ impl_node_port_send_command(struct spa_node *node,
 static int impl_node_process(struct spa_node *node)
 {
 	struct node *this = SPA_CONTAINER_OF(node, struct node, node);
-	uint64_t cmd = 1;
+	struct impl *impl = this->impl;
 
-	pw_log_trace("client-node %p: send process", this);
-
-	if (write(this->writefd, &cmd, 8) != 8)
-		spa_log_warn(this->log, "node %p: error flushing : %s", this, strerror(errno));
-
-	return SPA_STATUS_OK;
+	if (impl->this.node->driver)
+		return SPA_STATUS_HAVE_BUFFER;
+	else {
+		send_process(this);
+		return SPA_STATUS_OK;
+	}
 }
 
 static void
@@ -1091,7 +1150,6 @@ static void node_initialized(void *data)
 	struct pw_client_node *this = &impl->this;
 	struct pw_node *node = this->node;
 	struct pw_type *t = impl->t;
-	struct mem *m;
 
 	if (this->resource == NULL)
 		return;
@@ -1113,8 +1171,7 @@ static void node_initialized(void *data)
 			      &impl->io_areas) < 0)
                 return;
 
-	m = ensure_mem(impl, impl->io_areas->fd, t->data.MemFd, impl->io_areas->flags);
-	impl->io_memid = m->id;
+	ensure_mem(impl, impl->io_areas->fd, t->data.MemFd, impl->io_areas->flags);
 	pw_log_debug("client-node %p: io areas %p", node, impl->io_areas->ptr);
 
 	pw_client_node_resource_transport(this->resource,
@@ -1218,11 +1275,18 @@ static void node_port_added(void *data, struct pw_port *port)
 	port->owner_data = impl;
 }
 
+static void node_finish(void *data)
+{
+	struct impl *impl = data;
+	send_process(&impl->node);
+}
+
 static const struct pw_node_events node_events = {
 	PW_VERSION_NODE_EVENTS,
 	.free = node_free,
 	.initialized = node_initialized,
 	.port_added = node_port_added,
+	.finish = node_finish,
 };
 
 static const struct pw_resource_events resource_events = {