From ceb24f656e6af5e24e36008b5a2f8b386db857a8 Mon Sep 17 00:00:00 2001
From: Billy Kozak <bkozak@scanimetrics.com>
Date: Mon, 20 Jul 2015 10:28:24 -0600
Subject: [PATCH] Improved style of read_frame

- moved variable declaration to top of function in accordance with the
  Contiki style guide
- made function flatter, reduced nesting to improve readability
---
 cpu/cc26xx/dev/cc26xx-rf.c | 54 ++++++++++++++++++++++----------------
 1 file changed, 32 insertions(+), 22 deletions(-)

diff --git a/cpu/cc26xx/dev/cc26xx-rf.c b/cpu/cc26xx/dev/cc26xx-rf.c
index b26771a8a..efeee8450 100644
--- a/cpu/cc26xx/dev/cc26xx-rf.c
+++ b/cpu/cc26xx/dev/cc26xx-rf.c
@@ -1328,35 +1328,45 @@ send(const void *payload, unsigned short payload_len)
   return transmit(payload_len);
 }
 /*---------------------------------------------------------------------------*/
+static void
+release_data_entry(void)
+{
+  /* Clear the length byte */
+  rx_read_entry[8] = 0;
+  /* Set status to 0 "Pending" in element */
+  GET_FIELD_V(rx_read_entry, dataEntry, status) = DATA_ENTRY_STATUS_PENDING;
+  rx_read_entry = GET_FIELD_V(rx_read_entry, dataEntry, pNextEntry);
+}
+/*---------------------------------------------------------------------------*/
 static int
 read_frame(void *buf, unsigned short buf_len)
 {
+  int8_t rssi;
   int len = 0;
+  uint8_t status = GET_FIELD_V(rx_read_entry, dataEntry, status);
 
-  if(GET_FIELD_V(rx_read_entry, dataEntry, status) == DATA_ENTRY_STATUS_FINISHED) {
-
-    if(rx_read_entry[8] > 0) {
-      memcpy(buf, (char *)&rx_read_entry[9], buf_len);
-
-      /* Remove the footer */
-      len = MIN(buf_len, rx_read_entry[8] - 4);
-
-      int rssi = (int8_t)rx_read_entry[9 + len + 2];
-
-      packetbuf_set_attr(PACKETBUF_ATTR_RSSI, rssi);
-      RIMESTATS_ADD(llrx);
-
-      /* Clear the length byte */
-      rx_read_entry[8] = 0;
-    }
-
-    /* Set status to 0 "Pending" in element */
-    GET_FIELD_V(rx_read_entry, dataEntry, status) = DATA_ENTRY_STATUS_PENDING;
-
-    /* Move read entry pointer to next entry */
-    rx_read_entry = GET_FIELD_V(rx_read_entry, dataEntry, pNextEntry);
+  if(status != DATA_ENTRY_STATUS_FINISHED) {
+    /* No available data */
+    return 0;
   }
 
+  if(!rx_read_entry[8]) {
+    release_data_entry();
+    return 0;
+  }
+
+  memcpy(buf, (char *)&rx_read_entry[9], buf_len);
+
+  /* Remove the footer */
+  len = MIN(buf_len, rx_read_entry[8] - 4);
+
+  rssi = (int8_t)rx_read_entry[9 + len + 2];
+
+  packetbuf_set_attr(PACKETBUF_ATTR_RSSI, rssi);
+  RIMESTATS_ADD(llrx);
+
+  release_data_entry();
+
   return len;
 }
 /*---------------------------------------------------------------------------*/