Avoid some harsh, inappropriate DEBUGASSERT's.

configs/clicker2-stm32/README.txt

@@ -686,6 +686,9 @@ Configurations
         some additional fixes for byte ordering in 16-bit and 64-bit
         compressed IPv6 addresses, then all tests are working as expected:
         TCP, UDP, Telnet.
+      2017-08-5:  It looks like I have lost one of my Clicker2-STM32 boards.
+        This means that I will not be able to do any regression testing as
+        changes are made to the radio interfaces and 6LoWPAN :(
 
   nsh:
 

drivers/wireless/spirit/drivers/spirit_netdev.c

@@ -959,9 +959,22 @@ static void spirit_interrupt_work(FAR void *arg)
   if (irqstatus.IRQ_RX_FIFO_ERROR != 0)
     {
       wlwarn("WARNING: Rx FIFO Error\n");
-      DEBUGVERIFY(spirit_command(spirit, CMD_FLUSHRXFIFO));
 
+      /* Discard RX data */
+
+      DEBUGVERIFY(spirit_command(spirit, CMD_FLUSHRXFIFO));
+      irqstatus.IRQ_RX_DATA_READY = 0;
+      irqstatus.IRQ_VALID_SYNC    = 0;
+
+      /* Revert the receiving state */
+
+      if (priv->state == DRIVER_STATE_RECEIVING)
+        {
           priv->state = DRIVER_STATE_IDLE;
+        }
+
+      /* Update error statistics */
+
       NETDEV_RXERRORS(&priv->radio.r_dev);
       NETDEV_ERRORS(&priv->radio.r_dev);
 
@@ -976,9 +989,21 @@ static void spirit_interrupt_work(FAR void *arg)
       irqstatus.IRQ_MAX_RE_TX_REACH != 0)
     {
       wlwarn("WARNING: Tx FIFO Error/Max retries\n");
-      DEBUGVERIFY(spirit_command(spirit, COMMAND_FLUSHTXFIFO));
 
+      /* Discard TX data */
+
+      DEBUGVERIFY(spirit_command(spirit, COMMAND_FLUSHTXFIFO));
+      irqstatus.IRQ_TX_DATA_SENT = 0;
+
+      /* Revert the sending state */
+
+      if (priv->state == DRIVER_STATE_SENDING)
+        {
           priv->state = DRIVER_STATE_IDLE;
+        }
+
+      /* Update error statistics */
+
       NETDEV_TXERRORS(&priv->radio.r_dev);
       NETDEV_ERRORS(&priv->radio.r_dev);
 
@@ -1031,9 +1056,17 @@ static void spirit_interrupt_work(FAR void *arg)
   if (irqstatus.IRQ_VALID_SYNC != 0)
     {
       wlinfo("Valid sync\n");
+
+      /* I have seen multiple Valid Sync interrupts following an RX error
+       * condition.
+       */
+
+      if (priv->state != DRIVER_STATE_RECEIVING)
+        {
           DEBUGASSERT(priv->state == DRIVER_STATE_IDLE);
           priv->state = DRIVER_STATE_RECEIVING;
         }
+    }
 
   /* The IRQ_RX_DATA_READY notifies that a new packet has been received */
 

net/sixlowpan/sixlowpan_utils.c

@@ -124,8 +124,6 @@
 #ifdef HAVE_BYTEADDR
 static void sixlowpan_baddrfromip(const net_ipv6addr_t ipaddr, FAR uint8_t *baddr)
 {
-  DEBUGASSERT(ipaddr[0] == HTONS(0xfe80));
-
   /* Big-endian uint16_t to byte order */
 
   baddr[0] = ipaddr[7] >> 8 ^ 0x02;
@@ -135,8 +133,6 @@ static void sixlowpan_baddrfromip(const net_ipv6addr_t ipaddr, FAR uint8_t *badd
 #ifdef HAVE_SADDR
 static void sixlowpan_saddrfromip(const net_ipv6addr_t ipaddr, FAR uint8_t *saddr)
 {
-  DEBUGASSERT(ipaddr[0] == HTONS(0xfe80));
-
   /* Big-endian uint16_t to byte order */
 
   saddr[0]  = ipaddr[7] >> 8;
@@ -181,7 +177,7 @@ static void sixlowpan_eaddrfromip(const net_ipv6addr_t ipaddr, FAR uint8_t *eadd
  *
  *    128  112  96   80    64   48   32   16
  *    ---- ---- ---- ----  ---- ---- ---- ----
- *    fe80 0000 0000 0000  0000 00ff fe00 xx00 1-byte short address IEEE 48-bit MAC
+ *    xxxx 0000 0000 0000  0000 00ff fe00 xx00 1-byte short address IEEE 48-bit MAC
  *    xxxx 0000 0000 0000  0000 00ff fe00 xxxx 2-byte short address IEEE 48-bit MAC
  *    xxxx 0000 0000 0000  xxxx xxxx xxxx xxxx 8-byte extended address IEEE EUI-64
  *
@@ -218,6 +214,16 @@ int sixlowpan_destaddrfromip(FAR struct sixlowpan_driver_s *radio,
 
    /* Otherwise, the destination MAC address is encoded in the IP address */
 
+   /* Check for compressible link-local address.
+    * REVISIT:  This should not restrict us to link-local addresses.
+    */
+
+  if (ipaddr[0] != HTONS(0xfe80) || ipaddr[1] != 0 ||
+      ipaddr[2] != 0             || ipaddr[3] != 0)
+    {
+      return -EADDRNOTAVAIL;
+    }
+
 #ifdef CONFIG_WIRELESS_PKTRADIO
   /* If this is a packet radio, then we cannot know the correct size of the
    * radio's MAC address without asking.  The setting CONFIG_PKTRADIO_ADDRLEN
@@ -242,8 +248,6 @@ int sixlowpan_destaddrfromip(FAR struct sixlowpan_driver_s *radio,
           return ret;
         }
 
-      DEBUGASSERT(ipaddr[0] == HTONS(0xfe80));
-
 #ifdef HAVE_BYTEADDR
       if (properties.sp_addrlen == 1 &&
           SIXLOWPAN_IS_IID_8BIT_COMPRESSABLE(ipaddr))