From 63ea56256885b376d6fdfa3845bb81dbb8486924 Mon Sep 17 00:00:00 2001
From: simonduq <simonduq@sics.se>
Date: Mon, 26 Mar 2012 22:49:28 +0200
Subject: [PATCH] base encounter_time on the time before last strobe, remove
 unused previous_txtime

---
 core/net/mac/contikimac.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/core/net/mac/contikimac.c b/core/net/mac/contikimac.c
index 93bf4f5ea..ded95cada 100644
--- a/core/net/mac/contikimac.c
+++ b/core/net/mac/contikimac.c
@@ -522,7 +522,7 @@ static int
 send_packet(mac_callback_t mac_callback, void *mac_callback_ptr, struct rdc_buf_list *buf_list)
 {
   rtimer_clock_t t0;
-  rtimer_clock_t encounter_time = 0, previous_txtime = 0;
+  rtimer_clock_t encounter_time = 0;
   int strobes;
   uint8_t got_strobe_ack = 0;
   int hdrlen, len;
@@ -723,7 +723,6 @@ send_packet(mac_callback_t mac_callback, void *mac_callback_ptr, struct rdc_buf_
   watchdog_periodic();
   t0 = RTIMER_NOW();
   seqno = packetbuf_attr(PACKETBUF_ATTR_MAC_SEQNO);
-  previous_txtime = RTIMER_NOW();
   for(strobes = 0, collisions = 0;
       got_strobe_ack == 0 && collisions == 0 &&
       RTIMER_CLOCK_LT(RTIMER_NOW(), t0 + STROBE_TIME); strobes++) {
@@ -751,7 +750,7 @@ send_packet(mac_callback_t mac_callback, void *mac_callback_ptr, struct rdc_buf_
       if(ret == RADIO_TX_OK) {
         if(!is_broadcast) {
           got_strobe_ack = 1;
-          encounter_time = previous_txtime;
+          encounter_time = txtime;
           break;
         }
       } else if (ret == RADIO_TX_NOACK) {
@@ -776,7 +775,7 @@ send_packet(mac_callback_t mac_callback, void *mac_callback_ptr, struct rdc_buf_
         len = NETSTACK_RADIO.read(ackbuf, ACK_LEN);
         if(len == ACK_LEN && seqno == ackbuf[ACK_LEN-1]) {
           got_strobe_ack = 1;
-          encounter_time = previous_txtime;
+          encounter_time = txtime;
           break;
         } else {
           PRINTF("contikimac: collisions while sending\n");
@@ -784,8 +783,6 @@ send_packet(mac_callback_t mac_callback, void *mac_callback_ptr, struct rdc_buf_
         }
       }
 #endif /* RDC_CONF_HARDWARE_ACK */
-
-      previous_txtime = txtime;
     }
   }