DriverSAM: let gmac_dev_read() return the proper length (version 2) (#1000)

* Atmel SAM driver: let gmac_dev_read() return the proper length (version 2)

* Running uncrustify

* A minor format change

* Added a comment about a min() test

Author: htibosch

source/portable/NetworkInterface/DriverSAM/NetworkInterface.c

@@ -687,8 +687,10 @@ static BaseType_t prvGMACInit( NetworkInterface_t * pxInterface )
     GMAC->GMAC_NCR |= GMAC_NCR_MPE;
 
     memset( &gmac_option, '\0', sizeof( gmac_option ) );
-    gmac_option.uc_copy_all_frame = 0;
-    gmac_option.uc_no_boardcast = 0;
+
+    /* Note that 'gmac_option.uc_copy_all_frame' is false, do not copy all frames.
+     * And 'gmac_option.uc_no_boardcast' is false, meaning that broadcast is received.
+     * 'boardcast' is a typo. */
     memcpy( gmac_option.uc_mac_addr, pxEndPoint->xMACAddress.ucBytes, sizeof( gmac_option.uc_mac_addr ) );
 
     gs_gmac_dev.p_hw = GMAC;
@@ -697,7 +699,8 @@ static BaseType_t prvGMACInit( NetworkInterface_t * pxInterface )
     NVIC_SetPriority( GMAC_IRQn, configMAC_INTERRUPT_PRIORITY );
     NVIC_EnableIRQ( GMAC_IRQn );
 
-    /* Clear the hash table for multicast MAC addresses. */
+    /* Clear the hash table for multicast MAC addresses.
+     * OR set both to ~0H to receive all multicast packets. */
     GMAC->GMAC_HRB = 0U; /* Hash Register Bottom. */
     GMAC->GMAC_HRT = 0U; /* Hash Register Top. */
 
@@ -1031,6 +1034,7 @@ static uint32_t prvEMACRxPoll( void )
             if( xSendEventStructToIPTask( &xRxEvent, xBlockTime ) != pdTRUE )
             {
                 /* xSendEventStructToIPTask() timed out. Release the descriptor. */
+                FreeRTOS_printf( ( "prvEMACRxPoll: Can not queue a packet!\n" ) );
                 xRelease = pdTRUE;
             }
         }
@@ -1042,7 +1046,6 @@ static uint32_t prvEMACRxPoll( void )
              * again. */
             vReleaseNetworkBufferAndDescriptor( pxNextNetworkBufferDescriptor );
             iptraceETHERNET_RX_EVENT_LOST();
-            FreeRTOS_printf( ( "prvEMACRxPoll: Can not queue return packet!\n" ) );
         }
 
         /* Now the buffer has either been passed to the IP-task,

source/portable/NetworkInterface/DriverSAM/gmac_SAM.c

@@ -624,29 +624,36 @@ uint32_t gmac_dev_read( gmac_device_t * p_gmac_dev,
         return GMAC_RX_NO_DATA;
     }
 
+    /* Return the number of bytes received. */
+    *p_rcv_size = bytesLeft;
+
     /* gmac_dev_poll has confirmed that there is a complete frame at
      * the current position 'ul_rx_idx'
      */
     nextIdx = p_gmac_dev->ul_rx_idx;
 
-    /* Read +2 bytes because buffers are aligned at -2 bytes */
-    bytesLeft = min( bytesLeft + 2, ( int32_t ) ul_frame_size );
-
     #if ( NETWORK_BUFFERS_CACHED != 0 ) && ( __DCACHE_PRESENT != 0 ) && defined( CONF_BOARD_ENABLE_CACHE )
         SCB_InvalidateDCache();
     #endif
 
     #if ( ipconfigZERO_COPY_RX_DRIVER == 0 )
         {
             /* The frame will be copied in 1 or 2 memcpy's */
-            if( ( p_frame != NULL ) && ( bytesLeft != 0 ) )
+            if( p_frame != NULL )
             {
                 const uint8_t * source;
                 int32_t left;
                 int32_t toCopy;
 
                 source = gs_uc_rx_buffer + nextIdx * GMAC_RX_UNITSIZE;
-                left = bytesLeft;
+
+                /* The driver receives frames up to 1514 bytes long.
+                 * The actual value of ul_frame_size is 1536, so the
+                 * following test is not really necessary:
+                 */
+
+                /* Read +2 bytes because buffers are aligned at -2 bytes */
+                left = min( bytesLeft + 2, ( int32_t ) ul_frame_size );
                 toCopy = ( GMAC_RX_BUFFERS - nextIdx ) * GMAC_RX_UNITSIZE;
 
                 if( toCopy > left )
@@ -696,8 +703,6 @@ uint32_t gmac_dev_read( gmac_device_t * p_gmac_dev,
 
     p_gmac_dev->ul_rx_idx = nextIdx;
 
-    *p_rcv_size = bytesLeft;
-
     return GMAC_OK;
 }