From 181213124bc2c30efa2988339c1f6e9f8559d5aa Mon Sep 17 00:00:00 2001
From: adamdunkels <adamdunkels>
Date: Tue, 2 Feb 2010 23:28:58 +0000
Subject: [PATCH] Added a configuration option for setting the MAC channel
 check rate (which must be a power of two). The configuration is independent
 of the MAC protocol.

---
 core/net/mac/cxmac.c |  4 ++--
 core/net/mac/lpp.c   |  4 ++--
 core/net/mac/mac.h   | 13 ++++++++++++-
 core/net/mac/xmac.c  |  4 ++--
 4 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/core/net/mac/cxmac.c b/core/net/mac/cxmac.c
index a5f20e119..281614ddd 100644
--- a/core/net/mac/cxmac.c
+++ b/core/net/mac/cxmac.c
@@ -28,7 +28,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * $Id: cxmac.c,v 1.6 2010/02/02 16:33:07 adamdunkels Exp $
+ * $Id: cxmac.c,v 1.7 2010/02/02 23:28:58 adamdunkels Exp $
  */
 
 /**
@@ -114,7 +114,7 @@ struct cxmac_hdr {
 #ifdef CXMAC_CONF_OFF_TIME
 #define DEFAULT_OFF_TIME (CXMAC_CONF_OFF_TIME)
 #else
-#define DEFAULT_OFF_TIME (RTIMER_ARCH_SECOND / 4 - DEFAULT_ON_TIME)
+#define DEFAULT_OFF_TIME (RTIMER_ARCH_SECOND / MAC_CHANNEL_CHECK_RATE - DEFAULT_ON_TIME)
 #endif
 
 #define DEFAULT_PERIOD (DEFAULT_OFF_TIME + DEFAULT_ON_TIME)
diff --git a/core/net/mac/lpp.c b/core/net/mac/lpp.c
index 52b71b55e..2c681111a 100644
--- a/core/net/mac/lpp.c
+++ b/core/net/mac/lpp.c
@@ -28,7 +28,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * $Id: lpp.c,v 1.29 2010/01/25 11:43:32 adamdunkels Exp $
+ * $Id: lpp.c,v 1.30 2010/02/02 23:28:58 adamdunkels Exp $
  */
 
 /**
@@ -90,7 +90,7 @@
 #ifdef LPP_CONF_OFF_TIME
 #define OFF_TIME LPP_CONF_OFF_TIME
 #else
-#define OFF_TIME (CLOCK_SECOND / 2 - LISTEN_TIME)
+#define OFF_TIME (CLOCK_SECOND / MAC_CHANNEL_CHECK_RATE - LISTEN_TIME)
 #endif /* LPP_CONF_OFF_TIME */
 
 #define PACKET_LIFETIME (LISTEN_TIME + OFF_TIME)
diff --git a/core/net/mac/mac.h b/core/net/mac/mac.h
index 684290661..43527bd4f 100644
--- a/core/net/mac/mac.h
+++ b/core/net/mac/mac.h
@@ -28,7 +28,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * $Id: mac.h,v 1.8 2010/01/25 11:43:32 adamdunkels Exp $
+ * $Id: mac.h,v 1.9 2010/02/02 23:28:58 adamdunkels Exp $
  */
 
 /**
@@ -90,4 +90,15 @@ enum {
   MAC_TX_ERR_FATAL,
 };
 
+#ifdef MAC_CONF_CHANNEL_CHECK_RATE
+#define MAC_CHANNEL_CHECK_RATE MAC_CONF_CHANNEL_CHECK_RATE
+#else /* MAC_CHANNEL_CHECK_RATE */
+#define MAC_CHANNEL_CHECK_RATE 4
+#endif /* MAC_CHANNEL_CHECK_RATE */
+
+#if (MAC_CHANNEL_CHECK_RATE & (MAC_CHANNEL_CHECK_RATE - 1)) != 0
+#error MAC_CONF_CHANNEL_CHECK_RATE must be a power of two (i.e., 1, 2, 4, 8, 16, 32, 64, ...).
+#error Change MAC_CONF_CHANNEL_CHECK_RATE in contiki-conf.h or in your Makefile.
+#endif
+
 #endif /* __MAC_H__ */
diff --git a/core/net/mac/xmac.c b/core/net/mac/xmac.c
index 102df223d..eb9374a62 100644
--- a/core/net/mac/xmac.c
+++ b/core/net/mac/xmac.c
@@ -28,7 +28,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * $Id: xmac.c,v 1.50 2010/01/28 13:40:47 adamdunkels Exp $
+ * $Id: xmac.c,v 1.51 2010/02/02 23:28:58 adamdunkels Exp $
  */
 
 /**
@@ -114,7 +114,7 @@ struct xmac_hdr {
 #ifdef XMAC_CONF_OFF_TIME
 #define DEFAULT_OFF_TIME (XMAC_CONF_OFF_TIME)
 #else
-#define DEFAULT_OFF_TIME (RTIMER_ARCH_SECOND / 4 - DEFAULT_ON_TIME)
+#define DEFAULT_OFF_TIME (RTIMER_ARCH_SECOND / MAC_CHANNEL_CHECK_RATE - DEFAULT_ON_TIME)
 #endif
 
 #define DEFAULT_PERIOD (DEFAULT_OFF_TIME + DEFAULT_ON_TIME)