return timestamp diff

diff --git a/avr/z180-serv.c b/avr/z180-serv.c
index c7869a68f310e0c38d484887e5488ec03ecf66ee..af1d8e06bc7b7d5c462f3212e3eec227ac401e35 100644 (file)
--- a/avr/z180-serv.c
+++ b/avr/z180-serv.c
@@ -114,10 +114,9 @@ void do_msg_echo(uint8_t subf, int len, uint8_t * msg)
 /* get timer */
 void do_msg_get_timer(uint8_t subf, int len, uint8_t * msg)
 {
-       (void)len; (void)msg;
-
-       uint32_t time_ms = get_timer(0);
+       uint32_t time_ms = (len >= 4) ? *(uint32_t *) msg : 0;
 
+       time_ms = get_timer(time_ms);
        msg_xmit(3, subf, sizeof(time_ms), (uint8_t *) &time_ms);
 }