diff --git a/spa/plugins/v4l2/v4l2-utils.c b/spa/plugins/v4l2/v4l2-utils.c
index 26aebc6eb..6a5d0a2a3 100644
--- a/spa/plugins/v4l2/v4l2-utils.c
+++ b/spa/plugins/v4l2/v4l2-utils.c
@@ -169,6 +169,7 @@ static int spa_v4l2_clear_buffers(struct impl *this)
 					d[0].maxsize - d[0].mapoffset);
 		}
 		if (SPA_FLAG_CHECK(b->flags, BUFFER_FLAG_ALLOCATED)) {
+			spa_log_debug(this->log, "v4l2: close %d", (int) d[0].fd);
 			close(d[0].fd);
 		}
 		d[0].type = SPA_ID_INVALID;
diff --git a/src/modules/module-client-node/client-node.c b/src/modules/module-client-node/client-node.c
index 1057d48a0..e920dde17 100644
--- a/src/modules/module-client-node/client-node.c
+++ b/src/modules/module-client-node/client-node.c
@@ -618,7 +618,7 @@ impl_node_port_set_param(void *object,
 	spa_return_val_if_fail(this != NULL, -EINVAL);
 	spa_return_val_if_fail(CHECK_PORT(this, direction, port_id), -EINVAL);
 
-	pw_log_debug(NAME" %p: port %d.%d add param %s %d", this,
+	pw_log_debug(NAME" %p: port %d.%d set param %s %d", this,
 			direction, port_id,
 			spa_debug_type_find_name(spa_type_param, id), id);
 
@@ -627,8 +627,7 @@ impl_node_port_set_param(void *object,
 	if (id == SPA_PARAM_Format) {
 		for (i = 0; i < MAX_MIX+1; i++) {
 			struct mix *mix = &port->mix[i];
-			if (mix->valid)
-				clear_buffers(this, mix);
+			clear_buffers(this, mix);
 		}
 	}
 	if (this->resource == NULL)
@@ -732,6 +731,9 @@ do_port_use_buffers(struct impl *impl,
 	if (!p->have_format)
 		return -EIO;
 
+	if (direction == SPA_DIRECTION_OUTPUT)
+		mix_id = SPA_ID_INVALID;
+
 	if ((mix = find_mix(p, mix_id)) == NULL || !mix->valid)
 		return -EINVAL;
 
@@ -1015,10 +1017,12 @@ static int client_node_port_buffers(void *data,
 	if (!p->have_format)
 		return -EIO;
 
+	if (direction == SPA_DIRECTION_OUTPUT)
+		mix_id = SPA_ID_INVALID;
+
 	if ((mix = find_mix(p, mix_id)) == NULL || !mix->valid)
 		return -EINVAL;
 
-
 	for (i = 0; i < n_buffers; i++) {
 		struct spa_buffer *oldbuf, *newbuf;