ieee802154_req_data: Don't modify the IOB until we are certain that no EINTR errors will occur. Otherwise, the retry will fail

configs/clicker2-stm32/README.txt

@@ -460,8 +460,7 @@ Configurations
 
            telnetd_daemon: ERROR: socket failure: 106
 
-       2017-06-20:  I am get EINTR errors from the MAC layer when trying the
+       2017-06-20:  Debug underway.. not yet functional.
-         udpclient tries to send messages.  Still under investigation.
 
   nsh:
 

net/sixlowpan/sixlowpan_framelist.c

@@ -444,6 +444,9 @@ int sixlowpan_queue_frames(FAR struct ieee802154_driver_s *ieee,
 
       /* Add the first frame to the IOB queue */
 
+      ninfo("Queuing frame io_len=%u io_offset=%u\n",
+            iob->io_len, iob->io_offset);
+
       qhead          = iob;
       qtail          = iob;
 
@@ -522,6 +525,9 @@ int sixlowpan_queue_frames(FAR struct ieee802154_driver_s *ieee,
 
           /* Add the next frame to the tail of the IOB queue */
 
+          ninfo("Queuing frame io_len=%u io_offset=%u\n",
+                iob->io_len, iob->io_offset);
+
           qtail->io_flink = iob;
           qtail           = iob;
 
@@ -544,6 +550,7 @@ int sixlowpan_queue_frames(FAR struct ieee802154_driver_s *ieee,
 
           /* And submit the frame to the MAC */
 
+          ninfo("Submitting framelist\n");
           ret = sixlowpan_frame_submit(ieee, &meta, iob);
           if (ret < 0)
             {
@@ -580,6 +587,9 @@ int sixlowpan_queue_frames(FAR struct ieee802154_driver_s *ieee,
 
       /* And submit the frame to the MAC */
 
+      ninfo("Submitting frame length=%u io_offset=%u\n",
+            iob->io_len, iob->io_offset);
+
       ret = sixlowpan_frame_submit(ieee, &meta, iob);
       if (ret < 0)
         {

wireless/ieee802154/mac802154_data.c

@@ -82,12 +82,15 @@ int mac802154_req_data(MACHANDLE mac,
   uint8_t mhr_len = 3;
   int ret;
 
+  wlinfo("Received frame io_len=%u io_offset=%u\n",
+         frame->io_offset, frame->io_len);
+
   /* Check the required frame size */
 
   if (frame->io_len > IEEE802154_MAX_PHY_PACKET_SIZE)
-  {
+    {
-    return -E2BIG;
+      return -E2BIG;
-  }
+    }
 
   /* Cast the first two bytes of the IOB to a uint16_t frame control field */
 
@@ -226,10 +229,9 @@ int mac802154_req_data(MACHANDLE mac,
    * here that created the header
    */
 
+  wlinfo("mhr_len=%u\n", mhr_len);
   DEBUGASSERT(mhr_len == frame->io_offset);
 
-  frame->io_offset = 0; /* Set the offset to 0 to include the header */
-
   /* Allocate the txdesc, waiting if necessary, allow interruptions */
 
   ret = mac802154_txdesc_alloc(priv, &txdesc, true);
@@ -243,6 +245,16 @@ int mac802154_req_data(MACHANDLE mac,
       return ret;
     }
 
+   /* Set the offset to 0 to include the header ( we do not want to
+    * modify the frame until AFTER the last place that -EINTR could
+    * be returned and could generate a retry.  Subsequent error returns
+    * are fatal and no retry should occur.
+    */
+
+  frame->io_offset = 0;
+
+  /* Then initialize the TX descriptor */
+
   txdesc->conf->handle = meta->msdu_handle;
   txdesc->frame = frame;
   txdesc->frametype = IEEE802154_FRAME_DATA;
@@ -269,7 +281,7 @@ int mac802154_req_data(MACHANDLE mac,
        */
 
       ret = -ENOTSUP;
-      goto errout_with_sem;
+      goto errout_with_txdesc;
     }
   else
     {
@@ -306,7 +318,7 @@ int mac802154_req_data(MACHANDLE mac,
           else
             {
               ret = -EINVAL;
-              goto errout_with_sem;
+              goto errout_with_txdesc;
             }
         }
       else
@@ -327,6 +339,9 @@ int mac802154_req_data(MACHANDLE mac,
 
   return OK;
 
+errout_with_txdesc:
+  /* REVISIT: Free TX descriptor, but preserve the IOB. */
+
 errout_with_sem:
   mac802154_givesem(&priv->exclsem);
   return ret;