diff --git a/arch/arm/src/lpc17xx/lpc17_allocateheap.c b/arch/arm/src/lpc17xx/lpc17_allocateheap.c
index 46d5d9e7a38fc25abd85c22ec705b86212712cb3..5bf4827999ab48a7a4f95dce827dc93727d70a43 100755
--- a/arch/arm/src/lpc17xx/lpc17_allocateheap.c
+++ b/arch/arm/src/lpc17xx/lpc17_allocateheap.c
@@ -57,6 +57,7 @@
****************************************************************************/
/* Configuration ************************************************************/
+/* The configured RAM start address must be the beginning of CPU SRAM */
#if CONFIG_DRAM_START != LPC17_SRAM_BASE
# warning "CONFIG_DRAM_START is not at LPC17_SRAM_BASE"
@@ -66,6 +67,8 @@
# define CONFIG_DRAM_END (LPC17_SRAM_BASE+LPC17_CPUSRAM_SIZE)
#endif
+/* The configured RAM size must be less then or equal to the CPU SRAM size */
+
#if CONFIG_DRAM_SIZE > LPC17_CPUSRAM_SIZE
# warning "CONFIG_DRAM_SIZE is larger than the size of CPU SRAM"
# undef CONFIG_DRAM_SIZE
@@ -76,13 +79,25 @@
# warning "CONFIG_DRAM_END is before end of CPU SRAM... not all of CPU SRAM used"
#endif
+/* Sanity checking */
+
#ifdef LPC17_HAVE_BANK0
-# if CONFIG_MM_REGIONS < 2
-# warning "CONFIG_MM_REGIONS < 2: AHB SRAM Bank(s) not included in HEAP"
+# if defined(LPC17_BANK0_HEAPSIZE) || defined(LPC17_HAVE_BANK1)
+# if CONFIG_MM_REGIONS < 2
+# warning "CONFIG_MM_REGIONS < 2: AHB SRAM Bank(s) not included in HEAP"
+# endif
+# if CONFIG_MM_REGIONS > 2
+# warning "CONFIG_MM_REGIONS > 2: Additional regions handled by application?"
+# endif
+# else
+# if CONFIG_MM_REGIONS > 1
+# warning "CONFIG_MM_REGIONS > 1: This MCU has no available AHB SRAM Bank0/1"
+# endif
# endif
#else
# if CONFIG_MM_REGIONS > 1
# warning "CONFIG_MM_REGIONS > 1: This MCU has no AHB SRAM Bank0/1"
+# warning " Other memory regions handled by application?"
# endif
#endif
@@ -131,22 +146,44 @@ void up_addregion(void)
/* Banks 0 and 1 are each 16Kb. If both are present, they occupy a
* contiguous 32Kb memory region.
*
- * If Ethernet is enabled, it will take all of bank 0 for packet
+ * If Ethernet is enabled, it will take some or all of bank 0 for packet
* buffering and descriptor tables.
*/
#ifdef LPC17_HAVE_BANK0
-# if defined(CONFIG_NET) && defined(CONFIG_LPC17_ETHERNET) && defined(LPC17_NETHCONTROLLERS)
-# ifdef LPC17_HAVE_BANK1
- mm_addregion((FAR void*)LPC17_SRAM_BANK1, LPC17_BANK1_SIZE);
-# endif
+
+ /* We have BANK0 (and, hence, possibly Bank1). Is Bank0 all used for
+ * Ethernet packet buffering? Or is there any part of Bank0 available for
+ * the heap.
+ */
+
+# ifdef LPC17_BANK0_HEAPSIZE
+
+ /* Some or all of Bank0 is available for the heap. Is Bank1 present? */
+
+# ifdef LPC17_HAVE_BANK1
+
+ /* Yes... the heap space available is the unused memory at the end of
+ * Bank0 plus all of Bank1.
+ */
+
+ mm_addregion((FAR void*)LPC17_BANK0_HEAPBASE, LPC17_BANK0_HEAPSIZE+LPC17_BANK1_SIZE);
# else
-# ifdef LPC17_HAVE_BANK1
- mm_addregion((FAR void*)LPC17_SRAM_BANK0, LPC17_BANK0_SIZE+LPC17_BANK1_SIZE);
-# else
- mm_addregion((FAR void*)LPC17_SRAM_BANK0, LPC17_BANK0_SIZE);
-# endif
+
+ /* No... only the unused memory at the end of Bank0 is available for the
+ * heap/
+ */
+
+ mm_addregion((FAR void*)LPC17_BANK0_HEAPBASE, LPC17_BANK0_HEAPSIZE);
+# endif
+# else
+
+ /* Nothing is available in Bank0. Is Bank1 available? */
+
+# ifdef LPC17_HAVE_BANK1
+ mm_addregion((FAR void*)LPC17_SRAM_BANK1, LPC17_BANK1_SIZE);
# endif
+# endif
#endif
}
#endif
diff --git a/arch/arm/src/lpc17xx/lpc17_emacram.h b/arch/arm/src/lpc17xx/lpc17_emacram.h
index 75137084e0b2c1e76b97fb557b2512dc8f27c3ec..3759ccb9ee9f264a52fbfa22d489587660f78fa6 100755
--- a/arch/arm/src/lpc17xx/lpc17_emacram.h
+++ b/arch/arm/src/lpc17xx/lpc17_emacram.h
@@ -41,20 +41,36 @@
************************************************************************************/
#include <nuttx/config.h>
-#if defined(CONFIG_NET) && defined(CONFIG_LPC17_ETHERNET)
-
#include "chip.h"
#include "lpc17_memorymap.h"
-/* Does this chip have and ethernet controller? */
-
-#if LPC17_NETHCONTROLLERS > 0
-
/************************************************************************************
* Pre-processor Definitions
************************************************************************************/
+/* Default, no-EMAC Case ************************************************************/
+/* Assume that all of AHB SRAM will be available for heap. If this is not true, then
+ * LPC17_BANK0_HEAPSIZE will be undefined and redefined below.
+ */
+
+#undef LPC17_BANK0_HEAPBASE
+#undef LPC17_BANK0_HEAPSIZE
+#ifdef LPC17_HAVE_BANK0
+# define LPC17_BANK0_HEAPBASE LPC17_SRAM_BANK0
+# define LPC17_BANK0_HEAPSIZE LPC17_BANK0_SIZE
+#endif
-/* Configuration ********************************************************************/
+/* Is networking enabled? Is the LPC17xx Ethernet device enabled? Does this chip have
+ * and Ethernet controlloer? Yes... then we will replace the above default definitions.
+ */
+
+#if defined(CONFIG_NET) && defined(CONFIG_LPC17_ETHERNET) && LPC17_NETHCONTROLLERS > 0
+
+/* EMAC RAM Configuration ***********************************************************/
+/* Is AHB SRAM available? */
+
+#ifndef LPC17_HAVE_BANK0
+# error "AHB SRAM Bank0 is not available for EMAC RAM"
+#endif
/* Number of Tx descriptors */
@@ -68,12 +84,43 @@
# define CONFIG_NET_NRXDESC 18
#endif
-/* All of AHB SRAM, Bank 0 is set aside for EMAC Tx and Rx descriptors. */
+/* Size of the region at the beginning of AHB SRAM 0 set set aside for the EMAC.
+ * This size must fit within AHB SRAM Bank 0 and also be a multiple of 32-bit
+ * words.
+ */
+
+#ifndef CONFIG_NET_EMACRAM_SIZE
+# define CONFIG_NET_EMACRAM_SIZE LPC17_BANK0_SIZE
+#endif
+
+#if CONFIG_NET_EMACRAM_SIZE > LPC17_BANK0_SIZE
+# error "EMAC RAM size cannot exceed the size of AHB SRAM Bank 0"
+#endif
+
+#if (CONFIG_NET_EMACRAM_SIZE & 3) != 0
+# error "EMAC RAM size must be in multiples of 32-bit words"
+#endif
+
+/* Determine is there is any meaning space left at the end of AHB Bank 0 that
+ * could be added to the heap.
+ */
+
+#undef LPC17_BANK0_HEAPBASE
+#undef LPC17_BANK0_HEAPSIZE
+#if CONFIG_NET_EMACRAM_SIZE < (LPC17_BANK0_SIZE-128)
+# define LPC17_BANK0_HEAPBASE (LPC17_SRAM_BANK0 + CONFIG_NET_EMACRAM_SIZE)
+# define LPC17_BANK0_HEAPSIZE (LPC17_BANK0_SIZE - CONFIG_NET_EMACRAM_SIZE)
+#endif
+
+/* Memory at the beginning of AHB SRAM, Bank 0 is set aside for EMAC Tx and Rx
+ * descriptors. The position is not controllable, only the size of the region
+ * is controllable.
+ */
#define LPC17_EMACRAM_BASE LPC17_SRAM_BANK0
-#define LPC17_EMACRAM_SIZE LPC17_BANK0_SIZE
+#define LPC17_EMACRAM_SIZE CONFIG_NET_EMACRAM_SIZE
-/* Descriptors Memory Layout ********************************************************/
+/* Descriptor Memory Layout *********************************************************/
/* EMAC DMA RAM and descriptor definitions. The configured number of descriptors
* will determine the organization and the size of the descriptor and status tables.
* There is a complex interaction between the maximum packet size (CONFIG_NET_BUFSIZE)
@@ -90,7 +137,7 @@
*
* An example with all of the details:
*
- * NTXDESC=18 NRXDESC=18 CONFIG_NET_BUFSIZE=420:
+ * NTXDESC=18 NRXDESC=18 CONFIG_NET_EMACRAM_SIZE=16Kb CONFIG_NET_BUFSIZE=420:
* LPC17_TXDESCTAB_SIZE = 18*8 = 144
* LPC17_TXSTATTAB_SIZE = 18*4 = 72
* LPC17_TXTAB_SIZE = 216
@@ -191,6 +238,5 @@
* Public Functions
************************************************************************************/
-#endif /* LPC17_NETHCONTROLLERS > 0 */
-#endif /* CONFIG_NET && CONFIG_LPC17_ETHERNET */
+#endif /* CONFIG_NET && CONFIG_LPC17_ETHERNET && LPC17_NETHCONTROLLERS > 0*/
#endif /* __ARCH_ARM_SRC_LPC17XX_LPC17_EMACRAM_H */
diff --git a/configs/mbed/README.txt b/configs/mbed/README.txt
index 01becd3df1552a8661ec4fcce9cb38bfc08b0938..6098fc88b248c58508cadb1864d54b1f8200b046 100755
--- a/configs/mbed/README.txt
+++ b/configs/mbed/README.txt
@@ -291,6 +291,7 @@ mbed Configuration Options
CONFIG_PHY_SPEED100 - Select 100Mbit vs. 10Mbit speed.
CONFIG_PHY_FDUPLEX - Select full (vs. half) duplex
+ CONFIG_NET_EMACRAM_SIZE - Size of EMAC RAM. Default: 16Kb
CONFIG_NET_NTXDESC - Configured number of Tx descriptors. Default: 18
CONFIG_NET_NRXDESC - Configured number of Rx descriptors. Default: 18
CONFIG_NET_PRIORITY - Ethernet interrupt priority. The is default is
diff --git a/configs/mbed/nsh/defconfig b/configs/mbed/nsh/defconfig
index d8f55906288b834a6dba37260d0622b57202b243..1cddaa924d75ea640ad3df1e5725118f0249af8f 100755
--- a/configs/mbed/nsh/defconfig
+++ b/configs/mbed/nsh/defconfig
@@ -188,6 +188,7 @@ CONFIG_UART3_2STOP=0
# CONFIG_PHY_AUTONEG - Enable auto-negotion
# CONFIG_PHY_SPEED100 - Select 100Mbit vs. 10Mbit speed.
# CONFIG_PHY_FDUPLEX - Select full (vs. half) duplex
+# CONFIG_NET_EMACRAM_SIZE - Size of EMAC RAM. Default: 16Kb
# CONFIG_NET_NTXDESC - Configured number of Tx descriptors. Default: 18
# CONFIG_NET_NRXDESC - Configured number of Rx descriptors. Default: 18
# CONFIG_NET_PRIORITY - Ethernet interrupt priority. The is default is
diff --git a/configs/nucleus2g/README.txt b/configs/nucleus2g/README.txt
index 229c69a9bd1d667550eb8f7d5ab0790eca6ba326..654fd90894c777a8d9a94d39afbe525bee927f0a 100755
--- a/configs/nucleus2g/README.txt
+++ b/configs/nucleus2g/README.txt
@@ -403,6 +403,7 @@ Nucleus 2G Configuration Options
CONFIG_PHY_SPEED100 - Select 100Mbit vs. 10Mbit speed.
CONFIG_PHY_FDUPLEX - Select full (vs. half) duplex
+ CONFIG_NET_EMACRAM_SIZE - Size of EMAC RAM. Default: 16Kb
CONFIG_NET_NTXDESC - Configured number of Tx descriptors. Default: 18
CONFIG_NET_NRXDESC - Configured number of Rx descriptors. Default: 18
CONFIG_NET_PRIORITY - Ethernet interrupt priority. The is default is
diff --git a/configs/nucleus2g/nsh/defconfig b/configs/nucleus2g/nsh/defconfig
index 0ae8f76a981959c2d1f9bdcacd0d71f1772cb6d6..447df77ba32346f79980e34644b8e368ea6501ae 100755
--- a/configs/nucleus2g/nsh/defconfig
+++ b/configs/nucleus2g/nsh/defconfig
@@ -188,6 +188,7 @@ CONFIG_UART3_2STOP=0
# CONFIG_PHY_AUTONEG - Enable auto-negotion
# CONFIG_PHY_SPEED100 - Select 100Mbit vs. 10Mbit speed.
# CONFIG_PHY_FDUPLEX - Select full (vs. half) duplex
+# CONFIG_NET_EMACRAM_SIZE - Size of EMAC RAM. Default: 16Kb
# CONFIG_NET_NTXDESC - Configured number of Tx descriptors. Default: 18
# CONFIG_NET_NRXDESC - Configured number of Rx descriptors. Default: 18
# CONFIG_NET_PRIORITY - Ethernet interrupt priority. The is default is
diff --git a/configs/nucleus2g/ostest/defconfig b/configs/nucleus2g/ostest/defconfig
index f55fc07f08d0afe1ce17ff5cd98dd6e6acff4d17..4f532128916070da4c9473eb39dc3e1a35da62f1 100755
--- a/configs/nucleus2g/ostest/defconfig
+++ b/configs/nucleus2g/ostest/defconfig
@@ -188,6 +188,7 @@ CONFIG_UART3_2STOP=0
# CONFIG_PHY_AUTONEG - Enable auto-negotion
# CONFIG_PHY_SPEED100 - Select 100Mbit vs. 10Mbit speed.
# CONFIG_PHY_FDUPLEX - Select full (vs. half) duplex
+# CONFIG_NET_EMACRAM_SIZE - Size of EMAC RAM. Default: 16Kb
# CONFIG_NET_NTXDESC - Configured number of Tx descriptors. Default: 18
# CONFIG_NET_NRXDESC - Configured number of Rx descriptors. Default: 18
# CONFIG_NET_PRIORITY - Ethernet interrupt priority. The is default is
diff --git a/configs/nucleus2g/usbserial/defconfig b/configs/nucleus2g/usbserial/defconfig
index 1b3d0fdfbec7976173636d0da2de3b1dbc4af9ae..aaed805b1584cf84210eded41ca003d8d7722579 100755
--- a/configs/nucleus2g/usbserial/defconfig
+++ b/configs/nucleus2g/usbserial/defconfig
@@ -188,6 +188,7 @@ CONFIG_UART3_2STOP=0
# CONFIG_PHY_AUTONEG - Enable auto-negotion
# CONFIG_PHY_SPEED100 - Select 100Mbit vs. 10Mbit speed.
# CONFIG_PHY_FDUPLEX - Select full (vs. half) duplex
+# CONFIG_NET_EMACRAM_SIZE - Size of EMAC RAM. Default: 16Kb
# CONFIG_NET_NTXDESC - Configured number of Tx descriptors. Default: 18
# CONFIG_NET_NRXDESC - Configured number of Rx descriptors. Default: 18
# CONFIG_NET_PRIORITY - Ethernet interrupt priority. The is default is
diff --git a/configs/nucleus2g/usbstorage/defconfig b/configs/nucleus2g/usbstorage/defconfig
index 8b21405a2097ece3a7aba31579b0693d65a939bb..fc0aa5f96be9be9e86ec229eb28f4755b43d4bb9 100755
--- a/configs/nucleus2g/usbstorage/defconfig
+++ b/configs/nucleus2g/usbstorage/defconfig
@@ -188,6 +188,7 @@ CONFIG_UART3_2STOP=0
# CONFIG_PHY_AUTONEG - Enable auto-negotion
# CONFIG_PHY_SPEED100 - Select 100Mbit vs. 10Mbit speed.
# CONFIG_PHY_FDUPLEX - Select full (vs. half) duplex
+# CONFIG_NET_EMACRAM_SIZE - Size of EMAC RAM. Default: 16Kb
# CONFIG_NET_NTXDESC - Configured number of Tx descriptors. Default: 18
# CONFIG_NET_NRXDESC - Configured number of Rx descriptors. Default: 18
# CONFIG_NET_PRIORITY - Ethernet interrupt priority. The is default is
diff --git a/configs/olimex-lpc1766stk/README.txt b/configs/olimex-lpc1766stk/README.txt
index 7aebf16ee65210356d9d4e39ffed2de576cbf2a6..65264b770beb67eb0e2518b225cae8d29c15072b 100755
--- a/configs/olimex-lpc1766stk/README.txt
+++ b/configs/olimex-lpc1766stk/README.txt
@@ -609,6 +609,7 @@ Olimex LPC1766-STK Configuration Options
CONFIG_PHY_SPEED100 - Select 100Mbit vs. 10Mbit speed.
CONFIG_PHY_FDUPLEX - Select full (vs. half) duplex
+ CONFIG_NET_EMACRAM_SIZE - Size of EMAC RAM. Default: 16Kb
CONFIG_NET_NTXDESC - Configured number of Tx descriptors. Default: 18
CONFIG_NET_NRXDESC - Configured number of Rx descriptors. Default: 18
CONFIG_NET_PRIORITY - Ethernet interrupt priority. The is default is
diff --git a/configs/olimex-lpc1766stk/nettest/defconfig b/configs/olimex-lpc1766stk/nettest/defconfig
index 2d36172c116cb1c08911fbbac451354f183900ef..be6fb996037ea8519dc3a6a59fab1eb12316eaa5 100755
--- a/configs/olimex-lpc1766stk/nettest/defconfig
+++ b/configs/olimex-lpc1766stk/nettest/defconfig
@@ -188,6 +188,7 @@ CONFIG_UART3_2STOP=0
# CONFIG_PHY_AUTONEG - Enable auto-negotion
# CONFIG_PHY_SPEED100 - Select 100Mbit vs. 10Mbit speed.
# CONFIG_PHY_FDUPLEX - Select full (vs. half) duplex
+# CONFIG_NET_EMACRAM_SIZE - Size of EMAC RAM. Default: 16Kb
# CONFIG_NET_NTXDESC - Configured number of Tx descriptors. Default: 18
# CONFIG_NET_NRXDESC - Configured number of Rx descriptors. Default: 18
# CONFIG_NET_PRIORITY - Ethernet interrupt priority. The is default is
diff --git a/configs/olimex-lpc1766stk/nsh/defconfig b/configs/olimex-lpc1766stk/nsh/defconfig
index 783070df68e94c8e1acbf734328b25245d308881..d8dcf573aecbc1a08f1b5b1eac7021c34679399d 100755
--- a/configs/olimex-lpc1766stk/nsh/defconfig
+++ b/configs/olimex-lpc1766stk/nsh/defconfig
@@ -188,6 +188,7 @@ CONFIG_UART3_2STOP=0
# CONFIG_PHY_AUTONEG - Enable auto-negotion
# CONFIG_PHY_SPEED100 - Select 100Mbit vs. 10Mbit speed.
# CONFIG_PHY_FDUPLEX - Select full (vs. half) duplex
+# CONFIG_NET_EMACRAM_SIZE - Size of EMAC RAM. Default: 16Kb
# CONFIG_NET_NTXDESC - Configured number of Tx descriptors. Default: 18
# CONFIG_NET_NRXDESC - Configured number of Rx descriptors. Default: 18
# CONFIG_NET_PRIORITY - Ethernet interrupt priority. The is default is
diff --git a/configs/olimex-lpc1766stk/ostest/defconfig b/configs/olimex-lpc1766stk/ostest/defconfig
index d0dc7385d321b0f6d6f3213c6623333c4a0daaa6..3b9eb5384c90e79daa916261691811fa13331ef7 100755
--- a/configs/olimex-lpc1766stk/ostest/defconfig
+++ b/configs/olimex-lpc1766stk/ostest/defconfig
@@ -188,6 +188,7 @@ CONFIG_UART3_2STOP=0
# CONFIG_PHY_AUTONEG - Enable auto-negotion
# CONFIG_PHY_SPEED100 - Select 100Mbit vs. 10Mbit speed.
# CONFIG_PHY_FDUPLEX - Select full (vs. half) duplex
+# CONFIG_NET_EMACRAM_SIZE - Size of EMAC RAM. Default: 16Kb
# CONFIG_NET_NTXDESC - Configured number of Tx descriptors. Default: 18
# CONFIG_NET_NRXDESC - Configured number of Rx descriptors. Default: 18
# CONFIG_NET_PRIORITY - Ethernet interrupt priority. The is default is
diff --git a/configs/olimex-lpc1766stk/thttpd/defconfig b/configs/olimex-lpc1766stk/thttpd/defconfig
index 4b2b5345edd261a44d6cf502ef39bb6348cf27f8..f8eebba352672129e7fd325f0e42f4f080063b4f 100755
--- a/configs/olimex-lpc1766stk/thttpd/defconfig
+++ b/configs/olimex-lpc1766stk/thttpd/defconfig
@@ -188,6 +188,7 @@ CONFIG_UART3_2STOP=0
# CONFIG_PHY_AUTONEG - Enable auto-negotion
# CONFIG_PHY_SPEED100 - Select 100Mbit vs. 10Mbit speed.
# CONFIG_PHY_FDUPLEX - Select full (vs. half) duplex
+# CONFIG_NET_EMACRAM_SIZE - Size of EMAC RAM. Default: 16Kb
# CONFIG_NET_NTXDESC - Configured number of Tx descriptors. Default: 18
# CONFIG_NET_NRXDESC - Configured number of Rx descriptors. Default: 18
# CONFIG_NET_PRIORITY - Ethernet interrupt priority. The is default is
diff --git a/configs/olimex-lpc1766stk/usbserial/defconfig b/configs/olimex-lpc1766stk/usbserial/defconfig
index acef97a79bbb2a2a168a6a7ea91562cdc27be72e..29b78e72b60d210e0c7c0a1f6264ae455a369fe2 100755
--- a/configs/olimex-lpc1766stk/usbserial/defconfig
+++ b/configs/olimex-lpc1766stk/usbserial/defconfig
@@ -188,6 +188,7 @@ CONFIG_UART3_2STOP=0
# CONFIG_PHY_AUTONEG - Enable auto-negotion
# CONFIG_PHY_SPEED100 - Select 100Mbit vs. 10Mbit speed.
# CONFIG_PHY_FDUPLEX - Select full (vs. half) duplex
+# CONFIG_NET_EMACRAM_SIZE - Size of EMAC RAM. Default: 16Kb
# CONFIG_NET_NTXDESC - Configured number of Tx descriptors. Default: 18
# CONFIG_NET_NRXDESC - Configured number of Rx descriptors. Default: 18
# CONFIG_NET_PRIORITY - Ethernet interrupt priority. The is default is
diff --git a/configs/olimex-lpc1766stk/usbstorage/defconfig b/configs/olimex-lpc1766stk/usbstorage/defconfig
index 033d42c5652f3d6a2e070152909a6fdc666253d5..99619b98ab510f296a2d08c129a98b8ab0aaaa6b 100755
--- a/configs/olimex-lpc1766stk/usbstorage/defconfig
+++ b/configs/olimex-lpc1766stk/usbstorage/defconfig
@@ -188,6 +188,7 @@ CONFIG_UART3_2STOP=0
# CONFIG_PHY_AUTONEG - Enable auto-negotion
# CONFIG_PHY_SPEED100 - Select 100Mbit vs. 10Mbit speed.
# CONFIG_PHY_FDUPLEX - Select full (vs. half) duplex
+# CONFIG_NET_EMACRAM_SIZE - Size of EMAC RAM. Default: 16Kb
# CONFIG_NET_NTXDESC - Configured number of Tx descriptors. Default: 18
# CONFIG_NET_NRXDESC - Configured number of Rx descriptors. Default: 18
# CONFIG_NET_PRIORITY - Ethernet interrupt priority. The is default is
diff --git a/net/send.c b/net/send.c
index 14b9cea9925e6d0b2f4ef8812bda952f5ebf285e..b3f1373765bd068d794d89d3b03dc65a1def52e4 100644
--- a/net/send.c
+++ b/net/send.c
@@ -268,13 +268,17 @@ static uint16_t send_interrupt(struct uip_driver_s *dev, void *pvconn,
* then the send won't actually make it out... it will be replaced with
* an ARP request.
*
- * NOTE: If we are actually harvesting IP addresses on incomming IP
- * packets, then this check should be necessary; the MAC mapping should
- * already be in the ARP table.
+ * NOTE 1: This could an expensive check if there are a lot of entries
+ * in the ARP table. Hence, we only check on the first packet -- when
+ * snd_sent is zero.
+ *
+ * NOTE 2: If we are actually harvesting IP addresses on incomming IP
+ * packets, then this check should not be necessary; the MAC mapping
+ * should already be in the ARP table.
*/
#ifndef CONFIG_NET_ARP_IPIN
- if (uip_arp_find(conn->ripaddr) != NULL)
+ if (pstate->snd_sent != 0 || uip_arp_find(conn->ripaddr) != NULL)
#endif
{
/* Update the amount of data sent (but not necessarily ACKed) */