diff --git a/src/trace/trace.c b/src/trace/trace.c
index fa3571ab1..d8d61d8f3 100644
--- a/src/trace/trace.c
+++ b/src/trace/trace.c
@@ -57,6 +57,7 @@ static struct {
 	struct trace_event *event_buffer_flush;
 	mtx_t lock;
 	bool init;
+	bool new;
 	uint64_t start_time;
 } trace = {
 	.init = false
@@ -92,6 +93,13 @@ static inline int get_process_id(void)
 }
 
 
+/**
+ * Init new trace json file
+ *
+ * @param json_file  json file for trace events
+ *
+ * @return 0 if success, otherwise errorcode
+ */
 int re_trace_init(const char *json_file)
 {
 	int err = 0;
@@ -130,6 +138,7 @@ int re_trace_init(const char *json_file)
 
 	trace.start_time = tmr_jiffies_usec();
 	trace.init = true;
+	trace.new = true;
 
 out:
 	if (err) {
@@ -142,6 +151,11 @@ int re_trace_init(const char *json_file)
 }
 
 
+/**
+ * Close and flush trace file
+ *
+ * @return 0 if success, otherwise errorcode
+ */
 int re_trace_close(void)
 {
 	int err = 0;
@@ -170,6 +184,11 @@ int re_trace_close(void)
 }
 
 
+/**
+ * Flush trace buffer (can be called multiple times)
+ *
+ * @return 0 if success, otherwise errorcode
+ */
 int re_trace_flush(void)
 {
 	int i, flush_count;
@@ -177,7 +196,6 @@ int re_trace_flush(void)
 	struct trace_event *e;
 	char json_arg[256];
 	char name[128];
-	static bool first = true;
 
 #ifndef RE_TRACE_ENABLED
 	return 0;
@@ -227,10 +245,10 @@ int re_trace_flush(void)
 		(void)re_fprintf(trace.f,
 			"%s{\"cat\":\"%s\",\"pid\":%i,\"tid\":%lu,\"ts\":%llu,"
 			"\"ph\":\"%c\",%s%s}",
-			first ? "" : ",\n",
+			trace.new ? "" : ",\n",
 			e->cat, e->pid, e->tid, e->ts - trace.start_time,
 			e->ph, name, str_isset(json_arg) ? json_arg : "");
-		first = false;
+		trace.new = false;
 	}
 
 	(void)fflush(trace.f);