Fixed bug causing jerky uploads on Duet 3 and 3 Mini Ethernet

17 files changed, 263 insertions, 474 deletions

diff --git a/src/Hardware/SAME5x/Ethernet/GmacInterface.cpp b/src/Hardware/SAME5x/Ethernet/GmacInterface.cpp
index 2f6a5988..b2c4ebc3 100644
--- a/src/Hardware/SAME5x/Ethernet/GmacInterface.cpp
+++ b/src/Hardware/SAME5x/Ethernet/GmacInterface.cpp
@@ -27,6 +27,8 @@ extern "C" {
 #include <RepRapFirmware.h>
 #include <RTOSIface/RTOSIface.h>
 #include <Platform/TaskPriorities.h>
+#include <Platform/RepRap.h>
+#include <Platform/Platform.h>
 
 extern Mutex lwipMutex;
 
@@ -39,11 +41,12 @@ constexpr size_t EthernetTaskStackWords = 300;
 static Task<EthernetTaskStackWords> ethernetTask;
 
 // Error counters
-unsigned int rxErrorCount;
-unsigned int rxBuffersNotFullyPopulatedCount;
-unsigned int txErrorCount;
-unsigned int txBufferNotFreeCount;
-unsigned int txBufferTooShortCount;
+static unsigned int rxErrorCount = 0;
+static unsigned int rxBuffersNotFullyPopulatedCount = 0;
+static unsigned int rxBufferNotAvailableCount = 0;
+static unsigned int txErrorCount = 0;
+static unsigned int txBufferNotFreeCount = 0;
+static unsigned int txBufferTooShortCount = 0;
 
 /** Network interface identifier. */
 #define IFNAME0               'e'
@@ -160,7 +163,7 @@ static void gmac_rx_populate_queue(struct gmac_device *p_gmac_dev, uint32_t star
 		if (p_gmac_dev->rx_pbuf[ul_index] == nullptr)
 		{
 			/* Allocate a new pbuf with the maximum size. */
-			pbuf * const p = pbuf_alloc(PBUF_RAW, (u16_t) GMAC_FRAME_LENTGH_MAX, PBUF_POOL);
+			pbuf * const p = pbuf_alloc(PBUF_RAW, (u16_t) GMAC_FRAME_LENGTH_MAX, PBUF_POOL);
 			if (p == nullptr)
 			{
 				LWIP_DEBUGF(NETIF_DEBUG, ("gmac_rx_populate_queue: pbuf allocation failure\n"));
@@ -173,28 +176,18 @@ static void gmac_rx_populate_queue(struct gmac_device *p_gmac_dev, uint32_t star
 			LWIP_ASSERT("gmac_rx_populate_queue: pbuf size too small!", pbuf_clen(p) <= 1);
 
 			/* Make sure that the payload buffer is properly aligned. */
-			LWIP_ASSERT("gmac_rx_populate_queue: unaligned p->payload buffer address",
-					(((uint32_t)p->payload & 0xFFFFFFFC) == (uint32_t)p->payload));
-
-			// dc42 do this first to avoid a race condition with DMA, because writing addr.val transfers ownership back to the GMAC, so it should be the last thing we do
-			/* Reset status value. */
-			p_gmac_dev->rx_desc[ul_index].status.val = 0;
+			LWIP_ASSERT("gmac_rx_populate_queue: unaligned p->payload buffer address", (((uint32_t)p->payload & 0xFFFFFFFC) == (uint32_t)p->payload));
 
 			/* Save pbuf pointer to be sent to lwIP upper layer. */
 			p_gmac_dev->rx_pbuf[ul_index] = p;
 
-			if (ul_index == GMAC_RX_BUFFERS - 1)
-			{
-				p_gmac_dev->rx_desc[ul_index].addr.val = (u32_t) p->payload | GMAC_RXD_WRAP;
-			}
-			else
-			{
-				p_gmac_dev->rx_desc[ul_index].addr.val = (u32_t) p->payload;
-			}
+			// dc42 do this first to avoid a race condition with DMA, because writing addr.val transfers ownership back to the GMAC, so it should be the last thing we do
+			p_gmac_dev->rx_desc[ul_index].status.val = 0;				// reset status value
+
+			__DSB();
+			p_gmac_dev->rx_desc[ul_index].addr.val =  (ul_index == GMAC_RX_BUFFERS - 1) ? (u32_t) p->payload | GMAC_RXD_WRAP : (u32_t) p->payload;
 			Cache::FlushBeforeDMASend(&p_gmac_dev->rx_desc[ul_index], sizeof(p_gmac_dev->rx_desc[ul_index]));
-			LWIP_DEBUGF(NETIF_DEBUG,
-					("gmac_rx_populate_queue: new pbuf allocated: %p [idx=%u]\n",
-					p, (unsigned int)ul_index));
+			LWIP_DEBUGF(NETIF_DEBUG, ("gmac_rx_populate_queue: new pbuf allocated: %p [idx=%u]\n", p, (unsigned int)ul_index));
 		}
 
 		++ul_index;
@@ -258,9 +251,13 @@ static void gmac_tx_init(struct gmac_device *ps_gmac_dev) noexcept
 		ps_gmac_dev->tx_desc[ul_index].status.val = GMAC_TXD_USED | GMAC_TXD_LAST;
 	}
 	ps_gmac_dev->tx_desc[ul_index - 1].status.val |= GMAC_TXD_WRAP;
+	Cache::FlushBeforeDMASend(ps_gmac_dev->tx_desc, sizeof(ps_gmac_dev->tx_desc));
 
 	/* Set transmit buffer queue base address pointer. */
 	gmac_set_tx_queue(GMAC, (uint32_t) &ps_gmac_dev->tx_desc[0]);
+
+	/* Clear error status. */
+	gmac_clear_tx_status(GMAC, GMAC_TX_ERRORS);
 }
 
 /**
@@ -308,16 +305,8 @@ static void gmac_low_level_init(struct netif *netif) noexcept
  * an err_t value if the packet couldn't be sent.
  */
 
-#include <General/Portability.h>
 static err_t gmac_low_level_output(netif *p_netif, struct pbuf *p) noexcept
 {
-#if 0
-	debugPrintf("%u %u %" PRIu32 "\n",
-				LoadBE16((const uint8_t*)p->payload + 0x24),			// destination port
-				LoadBE16((const uint8_t*)p->payload + 0x10),			// length
-				LoadBE32((const uint8_t*)p->payload + 0x26)				// sequence number
-		);
-#endif
 	gmac_device *const ps_gmac_dev = static_cast<gmac_device *>(p_netif->state);
 
 	while (true)
@@ -334,10 +323,7 @@ static err_t gmac_low_level_output(netif *p_netif, struct pbuf *p) noexcept
 			LINK_STATS_INC(link.drop);
 
 			/* Reinit TX descriptors. */
-			gmac_tx_init(ps_gmac_dev);
-
-			/* Clear error status. */
-			gmac_clear_tx_status(GMAC, GMAC_TX_ERRORS);
+			gmac_tx_init(ps_gmac_dev);			// this also clears the Tx errors
 
 			gmac_enable_transmit(GMAC, true);
 		}
@@ -397,11 +383,11 @@ static err_t gmac_low_level_output(netif *p_netif, struct pbuf *p) noexcept
  * \param netif the lwIP network interface structure for this ethernetif.
  *
  * \return a pbuf filled with the received packet (including MAC header).
- * 0 on memory error.
+ * nullptr if no received packet available.
  */
 static pbuf *gmac_low_level_input(struct netif *netif) noexcept
 {
-	gmac_device *ps_gmac_dev = static_cast<gmac_device *>(netif->state);
+	gmac_device *const ps_gmac_dev = static_cast<gmac_device *>(netif->state);
 
 	if (gmac_get_rx_status(GMAC) & GMAC_RX_ERRORS)
 	{
@@ -432,44 +418,55 @@ static pbuf *gmac_low_level_input(struct netif *netif) noexcept
 		return nullptr;
 	}
 
-	volatile gmac_rx_descriptor_t * const p_rx = &ps_gmac_dev->rx_desc[ps_gmac_dev->us_rx_idx];
+	if (gmac_get_rx_status(GMAC) & GMAC_RSR_BNA)
+	{
+		++rxBufferNotAvailableCount;
+		gmac_clear_rx_status(GMAC, GMAC_RSR_BNA);
+	}
+
+	/* Check if a packet has been received and processed by GMAC. */
+	uint32_t rxIdx = ps_gmac_dev->us_rx_idx;
+	volatile gmac_rx_descriptor_t * const p_rx = &ps_gmac_dev->rx_desc[rxIdx];
 	Cache::InvalidateAfterDMAReceive(p_rx, sizeof(gmac_rx_descriptor_t));
 
-	pbuf * const p = ((p_rx->addr.val & GMAC_RXD_OWNERSHIP) == GMAC_RXD_OWNERSHIP)
-						? ps_gmac_dev->rx_pbuf[ps_gmac_dev->us_rx_idx]
+	pbuf * p = ((p_rx->addr.val & GMAC_RXD_OWNERSHIP) != 0)
+					? ps_gmac_dev->rx_pbuf[rxIdx]
 							: nullptr;
 
 	/* Check if a packet has been received and processed by GMAC. */
 	if (p != nullptr)
 	{
-		/* Packet is a SOF since packet size is set to maximum. */
-		const uint32_t length = p_rx->status.val & GMAC_RXD_LEN_MASK;
+		const uint32_t status = p_rx->status.val;
+		const uint32_t length = status & GMAC_RXD_LEN_MASK;
 
 		/* Fetch pre-allocated pbuf. */
 		Cache::InvalidateAfterDMAReceive(p->payload, length);
-		p->len = length;
 
 		/* Remove this pbuf from its descriptor. */
-		ps_gmac_dev->rx_pbuf[ps_gmac_dev->us_rx_idx] = nullptr;
+		ps_gmac_dev->rx_pbuf[rxIdx] = nullptr;
 		ps_gmac_dev->rxPbufsFullyPopulated = false;
-		LWIP_DEBUGF(NETIF_DEBUG,
-				("gmac_low_level_input: DMA buffer %p received, size=%u [idx=%u]\n",
-				p, (unsigned int)length, (unsigned int)ps_gmac_dev->us_rx_idx));
-		/* Set pbuf total packet size. */
-		p->tot_len = length;
+		p->tot_len = p->len = length;
 		LINK_STATS_INC(link.recv);
 
-		ps_gmac_dev->us_rx_idx = (ps_gmac_dev->us_rx_idx + 1) % GMAC_RX_BUFFERS;
+		ps_gmac_dev->us_rx_idx = rxIdx = (rxIdx + 1) % GMAC_RX_BUFFERS;
 
+		if ((status & (GMAC_RXD_SOF | GMAC_RXD_EOF)) == (GMAC_RXD_SOF | GMAC_RXD_EOF))
+		{
 #if LWIP_STATS
-		lwip_rx_count += length;
+			lwip_rx_count += length;
 #endif
+		}
+		else
+		{
+			pbuf_free(p);
+			p = nullptr;
+		}
 	}
 
 	/* Fill empty descriptors with new pbufs. */
 	if (!ps_gmac_dev->rxPbufsFullyPopulated)
 	{
-		gmac_rx_populate_queue(ps_gmac_dev, ps_gmac_dev->us_rx_idx);
+		gmac_rx_populate_queue(ps_gmac_dev, rxIdx);
 	}
 
 	return p;
@@ -511,20 +508,18 @@ extern "C" [[noreturn]] void gmac_task(void *pvParameters) noexcept
  */
 bool ethernetif_input(struct netif *netif) noexcept
 {
-	struct eth_hdr *ethhdr;
-	struct pbuf *p;
-
 	/* Move received packet into a new pbuf. */
-	p = gmac_low_level_input(netif);
+	pbuf *const p = gmac_low_level_input(netif);
 	if (p == nullptr)
 	{
 		return false;
 	}
 
 	/* Points to packet payload, which starts with an Ethernet header. */
-	ethhdr = static_cast<struct eth_hdr*>(p->payload);
+	const eth_hdr *ethhdr = static_cast<struct eth_hdr*>(p->payload);
 
-	switch (lwip_htons(ethhdr->type)) {
+	switch (lwip_htons(ethhdr->type))
+	{
 		case ETHTYPE_IP:
 		case ETHTYPE_ARP:
 #if defined(PPPOE_SUPPORT) && PPPOE_SUPPORT
@@ -532,7 +527,8 @@ bool ethernetif_input(struct netif *netif) noexcept
 		case ETHTYPE_PPPOE:
 #endif /* PPPOE_SUPPORT */
 			/* Send packet to lwIP for processing. */
-			if (netif->input(p, netif) != ERR_OK) {
+			if (netif->input(p, netif) != ERR_OK)
+			{
 				LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_input: IP input error\n"));
 				/* Free buffer. */
 				pbuf_free(p);
@@ -723,12 +719,13 @@ void ethernetif_hardware_init() noexcept
 	/* Enable the copy of data into the buffers ignore broadcasts, and not copy FCS. */
 	gmac_enable_copy_all(GMAC, false);
 	gmac_disable_broadcast(GMAC, false);
+	GMAC->NCR.reg |= GMAC_NCFGR_RXCOEN;			// check IP, UDP and TCP checksums so that we don't need to do it in lwip
 
 #if SUPPORT_MULTICAST_DISCOVERY
 	// Without this code, we don't receive any multicast packets
-	GMAC->GMAC_NCFGR |= GMAC_NCFGR_MTIHEN;			// enable multicast hash reception
-	GMAC->GMAC_HRB = 0xFFFFFFFF;					// enable reception of all multicast frames
-	GMAC->GMAC_HRT = 0xFFFFFFFF;
+	GMAC->NCR.reg |= GMAC_NCFGR_MTIHEN;			// enable multicast hash reception
+	GMAC->HRB.reg = 0xFFFFFFFF;					// enable reception of all multicast frames
+	GMAC->HRT.reg = 0xFFFFFFFF;
 #endif
 
 	/* Set RX buffer size to 1536. */
@@ -758,7 +755,7 @@ void ethernetif_hardware_init() noexcept
 bool ethernetif_establish_link() noexcept
 {
 	/* Auto Negotiate, work in RMII mode. */
-	uint8_t result = ethernet_phy_auto_negotiate(GMAC, BOARD_GMAC_PHY_ADDR);
+	const uint8_t result = ethernet_phy_auto_negotiate(GMAC, BOARD_GMAC_PHY_ADDR);
 	if (result != GMAC_OK)
 	{
 		if (result != GMAC_TIMEOUT)
@@ -769,13 +766,6 @@ bool ethernetif_establish_link() noexcept
 		return false;
 	}
 
-	/* Establish ethernet link. */
-	if (ethernet_phy_set_link(GMAC, BOARD_GMAC_PHY_ADDR, 1) != GMAC_OK)
-	{
-		LWIP_DEBUGF(NETIF_DEBUG, ("gmac_low_level_init: set link ERROR!\n"));
-		return false;
-	}
-
 	return true;
 }
 
@@ -825,4 +815,11 @@ extern "C" uint32_t sys_now() noexcept
 	return millis();
 }
 
+void ethernetif_diagnostics(MessageType mtype) noexcept
+{
+	reprap.GetPlatform().MessageF(mtype, "Error counts: %u %u %u %u %u %u\nSocket states:",
+								rxErrorCount, rxBuffersNotFullyPopulatedCount, rxBufferNotAvailableCount, txErrorCount, txBufferNotFreeCount, txBufferTooShortCount);
+	rxErrorCount = rxBuffersNotFullyPopulatedCount = rxBufferNotAvailableCount = txErrorCount = txBufferNotFreeCount = txBufferTooShortCount = 0;
+}
+
 // End
diff --git a/src/Hardware/SAME5x/Ethernet/GmacInterface.h b/src/Hardware/SAME5x/Ethernet/GmacInterface.h
index 0ef1f1e7..51026d5a 100644
--- a/src/Hardware/SAME5x/Ethernet/GmacInterface.h
+++ b/src/Hardware/SAME5x/Ethernet/GmacInterface.h
@@ -8,18 +8,15 @@
 #ifndef SRC_HARDWARE_SAME5X_ETHERNET_GMACINTERFACE_H_
 #define SRC_HARDWARE_SAME5X_ETHERNET_GMACINTERFACE_H_
 
-#ifdef __cplusplus
 extern "C" {
-#endif
-
 #include "lwip/err.h"
 #include "lwip/ip_addr.h"
 #include "lwip/netif.h"
 #include "netif/etharp.h"
-
-#ifdef __cplusplus
 }
 
+#include <Platform/MessageType.h>
+
 err_t ethernetif_init(struct netif *netif) noexcept;		// called by LwIP to initialise the interface
 
 void ethernetif_terminate() noexcept;						// called when we shut down
@@ -34,13 +31,6 @@ bool ethernetif_link_established() noexcept;				// asks the PHY if the link is s
 
 void ethernetif_set_mac_address(const uint8_t macAddress[]) noexcept;
 
-#endif
-
-// Error counters
-extern unsigned int rxErrorCount;
-extern unsigned int rxBuffersNotFullyPopulatedCount;
-extern unsigned int txErrorCount;
-extern unsigned int txBufferNotFreeCount;
-extern unsigned int txBufferTooShortCount;
+void ethernetif_diagnostics(MessageType mtype) noexcept;
 
 #endif /* SRC_HARDWARE_SAME5X_ETHERNET_GMACINTERFACE_H_ */
diff --git a/src/Hardware/SAME5x/Ethernet/conf_eth.h b/src/Hardware/SAME5x/Ethernet/conf_eth.h
index ebfd3161..6fd6ce95 100644
--- a/src/Hardware/SAME5x/Ethernet/conf_eth.h
+++ b/src/Hardware/SAME5x/Ethernet/conf_eth.h
@@ -21,7 +21,7 @@
 #define GMAC_TX_BUFFERS  4
 
 /** The MAC can support frame lengths up to 1536 bytes */
-#define GMAC_FRAME_LENTGH_MAX   1536
+#define GMAC_FRAME_LENGTH_MAX   1536
 
 /** MAC PHY operation max retry count */
 #define MAC_PHY_RETRY_MAX 1000000
diff --git a/src/Hardware/SAME5x/Ethernet/gmac.h b/src/Hardware/SAME5x/Ethernet/gmac.h
index c4eeafcb..1bdf6232 100644
--- a/src/Hardware/SAME5x/Ethernet/gmac.h
+++ b/src/Hardware/SAME5x/Ethernet/gmac.h
@@ -85,7 +85,7 @@ extern "C" {
 #define GMAC_TXD_LEN_MASK       (0x1FFF)    /**< Length of buffer */
 
 /** The MAC can support frame lengths up to 1536 bytes */
-#define GMAC_FRAME_LENTGH_MAX   1536
+#define GMAC_FRAME_LENGTH_MAX   1536
 
 #define GMAC_TX_UNITSIZE        (1518 + 2)  /**< Size for ETH frame length, rounded up to a multiple of 4 (may make the DMA more efficient) */
 
diff --git a/src/Hardware/SAME5x/Ethernet/ksz8081rna/ethernet_phy.c b/src/Hardware/SAME5x/Ethernet/ksz8081rna/ethernet_phy.c
index 81438cf0..271954c7 100644
--- a/src/Hardware/SAME5x/Ethernet/ksz8081rna/ethernet_phy.c
+++ b/src/Hardware/SAME5x/Ethernet/ksz8081rna/ethernet_phy.c
@@ -45,11 +45,6 @@
  */
 
 #include "ethernet_phy.h"
-
-#if 0	//dc42
-#include "pio/pio.h"
-#endif
-
 #include "../gmac.h"		// ASF3 gmac driver
 #include "conf_eth.h"
 
@@ -80,6 +75,8 @@ extern "C" {
 /* Ethernet PHY operation timeout */
 #define ETH_PHY_TIMEOUT 10
 
+extern void debugPrintf(const char *fmt, ...) noexcept;
+
 /**
  * \brief Find a valid PHY Address ( from addrStart to 31 ).
  *
@@ -89,8 +86,7 @@ extern "C" {
  *
  * \return 0xFF when no valid PHY address is found.
  */
-static uint8_t ethernet_phy_find_valid(Gmac *p_gmac, uint8_t uc_phy_addr,
-		uint8_t uc_start_addr)
+static uint8_t ethernet_phy_find_valid(Gmac *p_gmac, uint8_t uc_phy_addr, uint8_t uc_start_addr)
 {
 	uint32_t ul_value = 0;
 	uint8_t uc_rc = 0;
@@ -167,92 +163,6 @@ uint8_t ethernet_phy_init(Gmac *p_gmac, uint8_t uc_phy_addr, uint32_t mck)
 
 
 /**
- * \brief Get the Link & speed settings, and automatically set up the GMAC with the
- * settings.
- *
- * \param p_gmac   Pointer to the GMAC instance.
- * \param uc_phy_addr PHY address.
- * \param uc_apply_setting_flag Set to 0 to not apply the PHY configurations, else to apply.
- *
- * Return GMAC_OK if successfully, GMAC_TIMEOUT if timeout.
- */
-uint8_t ethernet_phy_set_link(Gmac *p_gmac, uint8_t uc_phy_addr,
-		uint8_t uc_apply_setting_flag)
-{
-	uint32_t ul_stat1;
-	uint32_t ul_stat2;
-	uint8_t uc_phy_address, uc_speed, uc_fd;
-	uint8_t uc_rc;
-
-	gmac_enable_management(p_gmac, true);
-
-	uc_phy_address = uc_phy_addr;
-
-	uc_rc = gmac_phy_read(p_gmac, uc_phy_address, GMII_BMSR, &ul_stat1);
-	if (uc_rc != GMAC_OK) {
-		/* Disable PHY management and start the GMAC transfer */
-		gmac_enable_management(p_gmac, false);
-
-		return uc_rc;
-	}
-
-	if ((ul_stat1 & GMII_LINK_STATUS) == 0) {
-		/* Disable PHY management and start the GMAC transfer */
-		gmac_enable_management(p_gmac, false);
-
-		return GMAC_INVALID;
-	}
-
-	if (uc_apply_setting_flag == 0) {
-		/* Disable PHY management and start the GMAC transfer */
-		gmac_enable_management(p_gmac, false);
-
-		return uc_rc;
-	}
-
-	/* Read advertisement */
-	uc_rc = gmac_phy_read(p_gmac, uc_phy_address, GMII_PCR1, &ul_stat2);
-	if (uc_rc != GMAC_OK) {
-		/* Disable PHY management and start the GMAC transfer */
-		gmac_enable_management(p_gmac, false);
-
-		return uc_rc;
-	}
-
-	if ((ul_stat1 & GMII_100BASE_TX_FD) && (ul_stat2 & GMII_OMI_100BASE_TX_FD)) {
-		/* Set GMAC for 100BaseTX and Full Duplex */
-		uc_speed = true;
-		uc_fd = true;
-	}
-
-	if ((ul_stat1 & GMII_10BASE_T_FD) && (ul_stat2 & GMII_OMI_10BASE_T_FD)) {
-		/* Set MII for 10BaseT and Full Duplex */
-		uc_speed = false;
-		uc_fd = true;
-	}
-
-	if ((ul_stat1 & GMII_100BASE_TX_HD) && (ul_stat2 & GMII_OMI_100BASE_TX_HD)) {
-		/* Set MII for 100BaseTX and Half Duplex */
-		uc_speed = true;
-		uc_fd = false;
-	}
-
-	if ((ul_stat1 & GMII_10BASE_T_HD) && (ul_stat2 & GMII_OMI_10BASE_T_HD)) {
-		/* Set MII for 10BaseT and Half Duplex */
-		uc_speed = false;
-		uc_fd = false;
-	}
-
-	gmac_set_speed(p_gmac, uc_speed);
-	gmac_enable_full_duplex(p_gmac, uc_fd);
-
-	/* Start the GMAC transfers */
-	gmac_enable_management(p_gmac, false);
-	return uc_rc;
-}
-
-
-/**
  * \brief Issue an auto negotiation of the PHY.
  *
  * \param p_gmac   Pointer to the GMAC instance.
@@ -295,8 +205,7 @@ uint8_t ethernet_phy_auto_negotiate(Gmac *p_gmac, uint8_t uc_phy_addr)
 		 * MII advertising for Next page.
 		 * 100BaseTxFD and HD, 10BaseTFD and HD, IEEE 802.3.
 		 */
-		ul_phy_anar = GMII_100TX_FDX | GMII_100TX_HDX | GMII_10_FDX | GMII_10_HDX |
-				GMII_AN_IEEE_802_3;
+		ul_phy_anar = GMII_100TX_FDX | GMII_100TX_HDX | GMII_10_FDX | GMII_10_HDX | GMII_AN_IEEE_802_3;
 		uc_rc = gmac_phy_write(p_gmac, uc_phy_addr, GMII_ANAR, ul_phy_anar);
 		if (uc_rc != GMAC_OK) {
 			gmac_enable_management(p_gmac, false);
diff --git a/src/Hardware/SAME5x/Ethernet/ksz8081rna/ethernet_phy.h b/src/Hardware/SAME5x/Ethernet/ksz8081rna/ethernet_phy.h
index 42098f13..ab5740b8 100644
--- a/src/Hardware/SAME5x/Ethernet/ksz8081rna/ethernet_phy.h
+++ b/src/Hardware/SAME5x/Ethernet/ksz8081rna/ethernet_phy.h
@@ -52,8 +52,8 @@
 // IEEE defined Registers
 #define GMII_BMCR        0x00   // Basic Control
 #define GMII_BMSR        0x01   // Basic Status
-#define GMII_PHYID1      0x02   // PHY Idendifier 1
-#define GMII_PHYID2      0x03   // PHY Idendifier 2
+#define GMII_PHYID1      0x02   // PHY Identifier 1
+#define GMII_PHYID2      0x03   // PHY Identifier 2
 #define GMII_ANAR        0x04   // Auto_Negotiation Advertisement
 #define GMII_ANLPAR      0x05   // Auto_negotiation Link Partner Ability
 #define GMII_ANER        0x06   // Auto-negotiation Expansion
diff --git a/src/Hardware/SAME70/Ethernet/GmacInterface.cpp b/src/Hardware/SAME70/Ethernet/GmacInterface.cpp
index 018bdad4..a0dad15e 100644
--- a/src/Hardware/SAME70/Ethernet/GmacInterface.cpp
+++ b/src/Hardware/SAME70/Ethernet/GmacInterface.cpp
@@ -56,6 +56,8 @@ extern "C" {
 #include <RepRapFirmware.h>
 #include <RTOSIface/RTOSIface.h>
 #include <Platform/TaskPriorities.h>
+#include <Platform/RepRap.h>
+#include <Platform/Platform.h>
 
 extern Mutex lwipMutex;
 
@@ -68,11 +70,12 @@ constexpr size_t EthernetTaskStackWords = 300;
 static Task<EthernetTaskStackWords> ethernetTask;
 
 // Error counters
-unsigned int rxErrorCount;
-unsigned int rxBuffersNotFullyPopulatedCount;
-unsigned int txErrorCount;
-unsigned int txBufferNotFreeCount;
-unsigned int txBufferTooShortCount;
+static unsigned int rxErrorCount = 0;
+static unsigned int rxBuffersNotFullyPopulatedCount = 0;
+static unsigned int rxBufferNotAvailableCount = 0;
+static unsigned int txErrorCount = 0;
+static unsigned int txBufferNotFreeCount = 0;
+static unsigned int txBufferTooShortCount = 0;
 
 /** Network interface identifier. */
 #define IFNAME0               'e'
@@ -89,7 +92,7 @@ unsigned int txBufferTooShortCount;
 /* configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY. */
 
 /** The GMAC interrupts to enable */
-#define GMAC_INT_GROUP (GMAC_ISR_RCOMP | GMAC_ISR_ROVR | GMAC_ISR_HRESP | GMAC_ISR_TCOMP | GMAC_ISR_TUR | GMAC_ISR_TFC)
+#define GMAC_INT_GROUP (GMAC_ISR_RCOMP | GMAC_ISR_ROVR)
 
 /** The GMAC TX errors to handle */
 #define GMAC_TX_ERRORS (GMAC_TSR_TFC | GMAC_TSR_HRESP)
@@ -160,9 +163,8 @@ uint32_t lwip_tx_rate = 0;
 uint32_t lwip_rx_rate = 0;
 #endif
 
-/**
- * \brief GMAC interrupt handler.
- */
+// GMAC interrupt handler
+// At present, we only use receive interrupts
 extern "C" void GMAC_Handler() noexcept
 {
 	/* Get interrupt status. */
@@ -194,7 +196,7 @@ static void gmac_rx_populate_queue(struct gmac_device *p_gmac_dev, uint32_t star
 		if (p_gmac_dev->rx_pbuf[ul_index] == nullptr)
 		{
 			/* Allocate a new pbuf with the maximum size. */
-			pbuf * const p = pbuf_alloc(PBUF_RAW, (u16_t) GMAC_FRAME_LENTGH_MAX, PBUF_POOL);
+			pbuf * const p = pbuf_alloc(PBUF_RAW, (u16_t) GMAC_FRAME_LENGTH_MAX, PBUF_POOL);
 			if (p == nullptr)
 			{
 				LWIP_DEBUGF(NETIF_DEBUG, ("gmac_rx_populate_queue: pbuf allocation failure\n"));
@@ -207,28 +209,18 @@ static void gmac_rx_populate_queue(struct gmac_device *p_gmac_dev, uint32_t star
 			LWIP_ASSERT("gmac_rx_populate_queue: pbuf size too small!", pbuf_clen(p) <= 1);
 
 			/* Make sure that the payload buffer is properly aligned. */
-			LWIP_ASSERT("gmac_rx_populate_queue: unaligned p->payload buffer address",
-					(((uint32_t)p->payload & 0xFFFFFFFC) == (uint32_t)p->payload));
-
-			// dc42 do this first to avoid a race condition with DMA, because writing addr.val transfers ownership back to the GMAC, so it should be the last thing we do
-			/* Reset status value. */
-			p_gmac_dev->rx_desc[ul_index].status.val = 0;
+			LWIP_ASSERT("gmac_rx_populate_queue: unaligned p->payload buffer address", (((uint32_t)p->payload & 0xFFFFFFFC) == (uint32_t)p->payload));
 
 			/* Save pbuf pointer to be sent to lwIP upper layer. */
 			p_gmac_dev->rx_pbuf[ul_index] = p;
 
-			if (ul_index == GMAC_RX_BUFFERS - 1)
-			{
-				p_gmac_dev->rx_desc[ul_index].addr.val = (u32_t) p->payload | GMAC_RXD_WRAP;
-			}
-			else
-			{
-				p_gmac_dev->rx_desc[ul_index].addr.val = (u32_t) p->payload;
-			}
+			// dc42 do this first to avoid a race condition with DMA, because writing addr.val transfers ownership back to the GMAC, so it should be the last thing we do
+			p_gmac_dev->rx_desc[ul_index].status.val = 0;				// reset status value
+
+			__DSB();
+			p_gmac_dev->rx_desc[ul_index].addr.val = (ul_index == GMAC_RX_BUFFERS - 1) ? (u32_t) p->payload | GMAC_RXD_WRAP : (u32_t) p->payload;
 			Cache::FlushBeforeDMASend(&p_gmac_dev->rx_desc[ul_index], sizeof(p_gmac_dev->rx_desc[ul_index]));
-			LWIP_DEBUGF(NETIF_DEBUG,
-					("gmac_rx_populate_queue: new pbuf allocated: %p [idx=%u]\n",
-					p, (unsigned int)ul_index));
+			LWIP_DEBUGF(NETIF_DEBUG, ("gmac_rx_populate_queue: new pbuf allocated: %p [idx=%u]\n", p, (unsigned int)ul_index));
 		}
 
 		++ul_index;
@@ -292,9 +284,13 @@ static void gmac_tx_init(struct gmac_device *ps_gmac_dev) noexcept
 		ps_gmac_dev->tx_desc[ul_index].status.val = GMAC_TXD_USED | GMAC_TXD_LAST;
 	}
 	ps_gmac_dev->tx_desc[ul_index - 1].status.val |= GMAC_TXD_WRAP;
+	Cache::FlushBeforeDMASend(ps_gmac_dev->tx_desc, sizeof(ps_gmac_dev->tx_desc));
 
 	/* Set transmit buffer queue base address pointer. */
 	gmac_set_tx_queue(GMAC, (uint32_t) &ps_gmac_dev->tx_desc[0]);
+
+	/* Clear error status. */
+	gmac_clear_tx_status(GMAC, GMAC_TX_ERRORS);
 }
 
 /**
@@ -323,7 +319,7 @@ static void gmac_low_level_init(struct netif *netif) noexcept
 	netif->flags |= NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP | NETIF_FLAG_IGMP;
 
 	/* Init MAC PHY driver. */
-	if (ethernet_phy_init(GMAC, BOARD_GMAC_PHY_ADDR, SystemCoreClock) != GMAC_OK)
+	if (ethernet_phy_init(GMAC, BOARD_GMAC_PHY_ADDR, SystemCoreClockFreq/2) != GMAC_OK)		// MCLK is half the core clock on the SAME70
 	{
 		LWIP_DEBUGF(NETIF_DEBUG, ("gmac_low_level_init: PHY init ERROR!\n"));
 		return;
@@ -359,10 +355,7 @@ static err_t gmac_low_level_output(netif *p_netif, struct pbuf *p) noexcept
 			LINK_STATS_INC(link.drop);
 
 			/* Reinit TX descriptors. */
-			gmac_tx_init(ps_gmac_dev);
-
-			/* Clear error status. */
-			gmac_clear_tx_status(GMAC, GMAC_TX_ERRORS);
+			gmac_tx_init(ps_gmac_dev);			// this also clears the Tx errors
 
 			gmac_enable_transmit(GMAC, true);
 		}
@@ -423,11 +416,11 @@ static err_t gmac_low_level_output(netif *p_netif, struct pbuf *p) noexcept
  * \param netif the lwIP network interface structure for this ethernetif.
  *
  * \return a pbuf filled with the received packet (including MAC header).
- * 0 on memory error.
+ * nullptr if no received packet available.
  */
 static pbuf *gmac_low_level_input(struct netif *netif) noexcept
 {
-	gmac_device *ps_gmac_dev = static_cast<gmac_device *>(netif->state);
+	gmac_device *const ps_gmac_dev = static_cast<gmac_device *>(netif->state);
 
 	if (gmac_get_rx_status(GMAC) & GMAC_RX_ERRORS)
 	{
@@ -458,45 +451,55 @@ static pbuf *gmac_low_level_input(struct netif *netif) noexcept
 		return nullptr;
 	}
 
-	volatile gmac_rx_descriptor_t * const p_rx = &ps_gmac_dev->rx_desc[ps_gmac_dev->us_rx_idx];
+	if (gmac_get_rx_status(GMAC) & GMAC_RSR_BNA)
+	{
+		++rxBufferNotAvailableCount;
+		gmac_clear_rx_status(GMAC, GMAC_RSR_BNA);
+	}
+
+	/* Check if a packet has been received and processed by GMAC. */
+	uint32_t rxIdx = ps_gmac_dev->us_rx_idx;
+	volatile gmac_rx_descriptor_t * const p_rx = &ps_gmac_dev->rx_desc[rxIdx];
 	Cache::InvalidateAfterDMAReceive(p_rx, sizeof(gmac_rx_descriptor_t));
-	pbuf * const p = ((p_rx->addr.val & GMAC_RXD_OWNERSHIP) == GMAC_RXD_OWNERSHIP)
-						? ps_gmac_dev->rx_pbuf[ps_gmac_dev->us_rx_idx]
-							: nullptr;
+	pbuf * p = ((p_rx->addr.val & GMAC_RXD_OWNERSHIP) != 0)
+					? ps_gmac_dev->rx_pbuf[rxIdx]
+						: nullptr;
 
 	/* Check if a packet has been received and processed by GMAC. */
 	if (p != nullptr)
 	{
-		/* Packet is a SOF since packet size is set to maximum. */
-		const uint32_t length = p_rx->status.val & GMAC_RXD_LEN_MASK;
+		const uint32_t status = p_rx->status.val;
+		const uint32_t length = status & GMAC_RXD_LEN_MASK;
 
 		/* Fetch pre-allocated pbuf. */
 		Cache::InvalidateAfterDMAReceive(p->payload, length);
-		p->len = length;
 
 		/* Remove this pbuf from its descriptor. */
-		ps_gmac_dev->rx_pbuf[ps_gmac_dev->us_rx_idx] = nullptr;
+		ps_gmac_dev->rx_pbuf[rxIdx] = nullptr;
 		ps_gmac_dev->rxPbufsFullyPopulated = false;
+		p->tot_len = p->len = length;
 
-		LWIP_DEBUGF(NETIF_DEBUG,
-				("gmac_low_level_input: DMA buffer %p received, size=%u [idx=%u]\n",
-				p, (unsigned int)length, (unsigned int)ps_gmac_dev->us_rx_idx));
-
-		/* Set pbuf total packet size. */
-		p->tot_len = length;
 		LINK_STATS_INC(link.recv);
 
-		ps_gmac_dev->us_rx_idx = (ps_gmac_dev->us_rx_idx + 1) % GMAC_RX_BUFFERS;
+		ps_gmac_dev->us_rx_idx = rxIdx = (rxIdx + 1) % GMAC_RX_BUFFERS;
 
+		if ((status & (GMAC_RXD_SOF | GMAC_RXD_EOF)) == (GMAC_RXD_SOF | GMAC_RXD_EOF))
+		{
 #if LWIP_STATS
-		lwip_rx_count += length;
+			lwip_rx_count += length;
 #endif
+		}
+		else
+		{
+			pbuf_free(p);
+			p = nullptr;
+		}
 	}
 
 	/* Fill empty descriptors with new pbufs. */
 	if (!ps_gmac_dev->rxPbufsFullyPopulated)
 	{
-		gmac_rx_populate_queue(ps_gmac_dev, ps_gmac_dev->us_rx_idx);
+		gmac_rx_populate_queue(ps_gmac_dev, rxIdx);
 	}
 
 	return p;
@@ -538,38 +541,37 @@ extern "C" [[noreturn]] void gmac_task(void *pvParameters) noexcept
  */
 bool ethernetif_input(struct netif *netif) noexcept
 {
-	struct eth_hdr *ethhdr;
-	struct pbuf *p;
-
 	/* Move received packet into a new pbuf. */
-	p = gmac_low_level_input(netif);
+	pbuf *const p = gmac_low_level_input(netif);
 	if (p == nullptr)
 	{
 		return false;
 	}
 
 	/* Points to packet payload, which starts with an Ethernet header. */
-	ethhdr = static_cast<struct eth_hdr*>(p->payload);
+	const eth_hdr *ethhdr = static_cast<struct eth_hdr*>(p->payload);
 
-	switch (lwip_htons(ethhdr->type)) {
-		case ETHTYPE_IP:
-		case ETHTYPE_ARP:
+	switch (lwip_htons(ethhdr->type))
+	{
+	case ETHTYPE_IP:
+	case ETHTYPE_ARP:
 #if defined(PPPOE_SUPPORT) && PPPOE_SUPPORT
-		case ETHTYPE_PPPOEDISC:
-		case ETHTYPE_PPPOE:
+	case ETHTYPE_PPPOEDISC:
+	case ETHTYPE_PPPOE:
 #endif /* PPPOE_SUPPORT */
-			/* Send packet to lwIP for processing. */
-			if (netif->input(p, netif) != ERR_OK) {
-				LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_input: IP input error\n"));
-				/* Free buffer. */
-				pbuf_free(p);
-			}
-			break;
-
-		default:
+		/* Send packet to lwIP for processing. */
+		if (netif->input(p, netif) != ERR_OK)
+		{
+			LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_input: IP input error\n"));
 			/* Free buffer. */
 			pbuf_free(p);
-			break;
+		}
+		break;
+
+	default:
+		/* Free buffer. */
+		pbuf_free(p);
+		break;
 	}
 	return true;
 }
@@ -654,6 +656,7 @@ void ethernetif_hardware_init() noexcept
 	/* Enable the copy of data into the buffers ignore broadcasts, and not copy FCS. */
 	gmac_enable_copy_all(GMAC, false);
 	gmac_disable_broadcast(GMAC, false);
+	GMAC->GMAC_NCFGR |= GMAC_NCFGR_RXCOEN;			// check IP, UDP and TCP checksums so that we don't need to do it in lwip
 
 #if SUPPORT_MULTICAST_DISCOVERY
 	// Without this code, we don't receive any multicast packets
@@ -712,7 +715,7 @@ void ethernetif_hardware_init() noexcept
 bool ethernetif_establish_link() noexcept
 {
 	/* Auto Negotiate, work in RMII mode. */
-	uint8_t result = ethernet_phy_auto_negotiate(GMAC, BOARD_GMAC_PHY_ADDR);
+	const uint8_t result = ethernet_phy_auto_negotiate(GMAC, BOARD_GMAC_PHY_ADDR);
 	if (result != GMAC_OK)
 	{
 		if (result != GMAC_TIMEOUT)
@@ -723,13 +726,6 @@ bool ethernetif_establish_link() noexcept
 		return false;
 	}
 
-	/* Establish ethernet link. */
-	if (ethernet_phy_set_link(GMAC, BOARD_GMAC_PHY_ADDR, 1) != GMAC_OK)
-	{
-		LWIP_DEBUGF(NETIF_DEBUG, ("gmac_low_level_init: set link ERROR!\n"));
-		return false;
-	}
-
 	return true;
 }
 
@@ -779,4 +775,11 @@ extern "C" uint32_t sys_now() noexcept
 	return millis();
 }
 
+void ethernetif_diagnostics(MessageType mtype) noexcept
+{
+	reprap.GetPlatform().MessageF(mtype, "Error counts: %u %u %u %u %u %u\nSocket states:",
+								rxErrorCount, rxBuffersNotFullyPopulatedCount, rxBufferNotAvailableCount, txErrorCount, txBufferNotFreeCount, txBufferTooShortCount);
+	rxErrorCount = rxBuffersNotFullyPopulatedCount = rxBufferNotAvailableCount = txErrorCount = txBufferNotFreeCount = txBufferTooShortCount = 0;
+}
+
 // End
diff --git a/src/Hardware/SAME70/Ethernet/GmacInterface.h b/src/Hardware/SAME70/Ethernet/GmacInterface.h
index 1cbe7ad9..86b490fb 100644
--- a/src/Hardware/SAME70/Ethernet/GmacInterface.h
+++ b/src/Hardware/SAME70/Ethernet/GmacInterface.h
@@ -45,18 +45,15 @@
 #ifndef SAME70_ETHERNET_GMACINTERFACE_H_INCLUDED
 #define SAME70_ETHERNET_GMACINTERFACE_H_INCLUDED
 
-#ifdef __cplusplus
 extern "C" {
-#endif
-
 #include "lwip/err.h"
 #include "lwip/ip_addr.h"
 #include "lwip/netif.h"
 #include "netif/etharp.h"
-
-#ifdef __cplusplus
 }
 
+#include <Platform/MessageType.h>
+
 err_t ethernetif_init(struct netif *netif) noexcept;		// called by LwIP to initialise the interface
 
 void ethernetif_terminate() noexcept;						// called when we shut down
@@ -71,13 +68,6 @@ bool ethernetif_link_established() noexcept;				// asks the PHY if the link is s
 
 void ethernetif_set_mac_address(const uint8_t macAddress[]) noexcept;
 
-#endif
-
-// Error counters
-extern unsigned int rxErrorCount;
-extern unsigned int rxBuffersNotFullyPopulatedCount;
-extern unsigned int txErrorCount;
-extern unsigned int txBufferNotFreeCount;
-extern unsigned int txBufferTooShortCount;
+void ethernetif_diagnostics(MessageType mtype) noexcept;
 
 #endif /* SAME70_ETHERNET_GMACINTERFACE_H_INCLUDED */
diff --git a/src/Hardware/SAME70/Ethernet/ksz8081rna/ethernet_phy.c b/src/Hardware/SAME70/Ethernet/ksz8081rna/ethernet_phy.c
index c185c1aa..3b8c2a86 100644
--- a/src/Hardware/SAME70/Ethernet/ksz8081rna/ethernet_phy.c
+++ b/src/Hardware/SAME70/Ethernet/ksz8081rna/ethernet_phy.c
@@ -46,10 +46,6 @@
 
 #include "ethernet_phy.h"
 
-#if 0	//dc42
-#include "pio/pio.h"
-#endif
-
 #include <gmac/gmac.h>		// ASF3 gmac driver
 #include "conf_eth.h"
 
@@ -77,14 +73,11 @@ extern "C" {
 /* Max PHY number */
 #define ETH_PHY_MAX_ADDR   31
 
-#if 0	// chrishamm
-/* Ethernet PHY operation max retry count */
-#define ETH_PHY_RETRY_MAX 1000000
-#endif
-
 /* Ethernet PHY operation timeout */
 #define ETH_PHY_TIMEOUT 10
 
+extern void debugPrintf(const char *fmt, ...) noexcept;
+
 /**
  * \brief Find a valid PHY Address ( from addrStart to 31 ).
  *
@@ -94,8 +87,7 @@ extern "C" {
  *
  * \return 0xFF when no valid PHY address is found.
  */
-static uint8_t ethernet_phy_find_valid(Gmac *p_gmac, uint8_t uc_phy_addr,
-		uint8_t uc_start_addr)
+static uint8_t ethernet_phy_find_valid(Gmac *p_gmac, uint8_t uc_phy_addr, uint8_t uc_start_addr)
 {
 	uint32_t ul_value = 0;
 	uint8_t uc_rc = 0;
@@ -150,12 +142,6 @@ uint8_t ethernet_phy_init(Gmac *p_gmac, uint8_t uc_phy_addr, uint32_t mck)
 	uint8_t uc_rc;
 	uint8_t uc_phy;
 
-#if 0	// chrishamm
-	pio_set_output(PIN_GMAC_RESET_PIO, PIN_GMAC_RESET_MASK, 1,  false, true);
-	pio_set_input(PIN_GMAC_INT_PIO, PIN_GMAC_INT_MASK, PIO_PULLUP);
-	pio_set_peripheral(PIN_GMAC_PIO, PIN_GMAC_PERIPH, PIN_GMAC_MASK);
-#endif
-
 	ethernet_phy_reset(GMAC,uc_phy_addr);
 
 	/* Configure GMAC runtime clock */
@@ -178,92 +164,6 @@ uint8_t ethernet_phy_init(Gmac *p_gmac, uint8_t uc_phy_addr, uint32_t mck)
 
 
 /**
- * \brief Get the Link & speed settings, and automatically set up the GMAC with the
- * settings.
- *
- * \param p_gmac   Pointer to the GMAC instance.
- * \param uc_phy_addr PHY address.
- * \param uc_apply_setting_flag Set to 0 to not apply the PHY configurations, else to apply.
- *
- * Return GMAC_OK if successfully, GMAC_TIMEOUT if timeout.
- */
-uint8_t ethernet_phy_set_link(Gmac *p_gmac, uint8_t uc_phy_addr,
-		uint8_t uc_apply_setting_flag)
-{
-	uint32_t ul_stat1;
-	uint32_t ul_stat2;
-	uint8_t uc_phy_address, uc_speed, uc_fd;
-	uint8_t uc_rc;
-
-	gmac_enable_management(p_gmac, true);
-
-	uc_phy_address = uc_phy_addr;
-
-	uc_rc = gmac_phy_read(p_gmac, uc_phy_address, GMII_BMSR, &ul_stat1);
-	if (uc_rc != GMAC_OK) {
-		/* Disable PHY management and start the GMAC transfer */
-		gmac_enable_management(p_gmac, false);
-
-		return uc_rc;
-	}
-
-	if ((ul_stat1 & GMII_LINK_STATUS) == 0) {
-		/* Disable PHY management and start the GMAC transfer */
-		gmac_enable_management(p_gmac, false);
-
-		return GMAC_INVALID;
-	}
-
-	if (uc_apply_setting_flag == 0) {
-		/* Disable PHY management and start the GMAC transfer */
-		gmac_enable_management(p_gmac, false);
-
-		return uc_rc;
-	}
-
-	/* Read advertisement */
-	uc_rc = gmac_phy_read(p_gmac, uc_phy_address, GMII_PCR1, &ul_stat2);
-	if (uc_rc != GMAC_OK) {
-		/* Disable PHY management and start the GMAC transfer */
-		gmac_enable_management(p_gmac, false);
-
-		return uc_rc;
-	}
-
-	if ((ul_stat1 & GMII_100BASE_TX_FD) && (ul_stat2 & GMII_OMI_100BASE_TX_FD)) {
-		/* Set GMAC for 100BaseTX and Full Duplex */
-		uc_speed = true;
-		uc_fd = true;
-	}
-
-	if ((ul_stat1 & GMII_10BASE_T_FD) && (ul_stat2 & GMII_OMI_10BASE_T_FD)) {
-		/* Set MII for 10BaseT and Full Duplex */
-		uc_speed = false;
-		uc_fd = true;
-	}
-
-	if ((ul_stat1 & GMII_100BASE_TX_HD) && (ul_stat2 & GMII_OMI_100BASE_TX_HD)) {
-		/* Set MII for 100BaseTX and Half Duplex */
-		uc_speed = true;
-		uc_fd = false;
-	}
-
-	if ((ul_stat1 & GMII_10BASE_T_HD) && (ul_stat2 & GMII_OMI_10BASE_T_HD)) {
-		/* Set MII for 10BaseT and Half Duplex */
-		uc_speed = false;
-		uc_fd = false;
-	}
-
-	gmac_set_speed(p_gmac, uc_speed);
-	gmac_enable_full_duplex(p_gmac, uc_fd);
-
-	/* Start the GMAC transfers */
-	gmac_enable_management(p_gmac, false);
-	return uc_rc;
-}
-
-
-/**
  * \brief Issue an auto negotiation of the PHY.
  *
  * \param p_gmac   Pointer to the GMAC instance.
@@ -274,10 +174,6 @@ uint8_t ethernet_phy_set_link(Gmac *p_gmac, uint8_t uc_phy_addr,
 static bool phyInitialized = false;
 uint8_t ethernet_phy_auto_negotiate(Gmac *p_gmac, uint8_t uc_phy_addr)
 {
-#if 0	// chrishamm
-	uint32_t ul_retry_max = ETH_PHY_RETRY_MAX;
-	uint32_t ul_retry_count = 0;
-#endif
 	uint32_t ul_value;
 	uint32_t ul_phy_anar;
 	uint32_t ul_phy_analpar;
@@ -310,8 +206,7 @@ uint8_t ethernet_phy_auto_negotiate(Gmac *p_gmac, uint8_t uc_phy_addr)
 		 * MII advertising for Next page.
 		 * 100BaseTxFD and HD, 10BaseTFD and HD, IEEE 802.3.
 		 */
-		ul_phy_anar = GMII_100TX_FDX | GMII_100TX_HDX | GMII_10_FDX | GMII_10_HDX |
-				GMII_AN_IEEE_802_3;
+		ul_phy_anar = GMII_100TX_FDX | GMII_100TX_HDX | GMII_10_FDX | GMII_10_HDX | GMII_AN_IEEE_802_3;
 		uc_rc = gmac_phy_write(p_gmac, uc_phy_addr, GMII_ANAR, ul_phy_anar);
 		if (uc_rc != GMAC_OK) {
 			gmac_enable_management(p_gmac, false);
@@ -345,7 +240,6 @@ uint8_t ethernet_phy_auto_negotiate(Gmac *p_gmac, uint8_t uc_phy_addr)
 	}
 
 	/* Check if auto negotiation is completed */
-#if 1	// chrishamm
 	uc_rc = gmac_phy_read(p_gmac, uc_phy_addr, GMII_BMSR, &ul_value);
 	if (uc_rc != GMAC_OK)
 	{
@@ -358,27 +252,6 @@ uint8_t ethernet_phy_auto_negotiate(Gmac *p_gmac, uint8_t uc_phy_addr)
 		gmac_enable_management(p_gmac, false);
 		return GMAC_TIMEOUT;
 	}
-#else
-	while (1) {
-		uc_rc = gmac_phy_read(p_gmac, uc_phy_addr, GMII_BMSR, &ul_value);
-		if (uc_rc != GMAC_OK) {
-			gmac_enable_management(p_gmac, false);
-			return uc_rc;
-		}
-		/* Done successfully */
-		if (ul_value & GMII_AUTONEG_COMP) {
-			break;
-		}
-
-		/* Timeout check */
-		if (ul_retry_max) {
-			if (++ul_retry_count >= ul_retry_max) {
-				gmac_enable_management(p_gmac, false);
-				return GMAC_TIMEOUT;
-			}
-		}
-	}
-#endif
 
 	/* Get the auto negotiate link partner base page */
 	uc_rc = gmac_phy_read(p_gmac, uc_phy_addr, GMII_ANLPAR, &ul_phy_analpar);
@@ -387,7 +260,6 @@ uint8_t ethernet_phy_auto_negotiate(Gmac *p_gmac, uint8_t uc_phy_addr)
 		return uc_rc;
 	}
 
-
 	/* Set up the GMAC link speed */
 	if ((ul_phy_anar & ul_phy_analpar) & GMII_100TX_FDX) {
 		/* Set MII for 100BaseTX and Full Duplex */
diff --git a/src/Hardware/SAME70/Ethernet/ksz8081rna/ethernet_phy.h b/src/Hardware/SAME70/Ethernet/ksz8081rna/ethernet_phy.h
index 85e93438..ab5740b8 100644
--- a/src/Hardware/SAME70/Ethernet/ksz8081rna/ethernet_phy.h
+++ b/src/Hardware/SAME70/Ethernet/ksz8081rna/ethernet_phy.h
@@ -47,7 +47,7 @@
 #ifndef ETHERNET_PHY_H_INCLUDED
 #define ETHERNET_PHY_H_INCLUDED
 
-#include "compiler.h"
+#include <Core.h>
 
 // IEEE defined Registers
 #define GMII_BMCR        0x00   // Basic Control
diff --git a/src/Networking/HttpResponder.cpp b/src/Networking/HttpResponder.cpp
index d910ef9f..6b75b418 100644
--- a/src/Networking/HttpResponder.cpp
+++ b/src/Networking/HttpResponder.cpp
@@ -1296,21 +1296,24 @@ void HttpResponder::DoUpload() noexcept
 	size_t len;
 	if (skt->ReadBuffer(buffer, len))
 	{
-		(void)CheckAuthenticated();							// uploading may take a long time, so make sure the requester IP is not timed out
-		timer = millis();									// reset the timer
+		do
+		{
+			(void)CheckAuthenticated();						// uploading may take a long time, so make sure the requester IP is not timed out
+			timer = millis();								// reset the timer
 
-		const bool ok = dummyUpload || fileBeingUploaded.Write(buffer, len);
-		skt->Taken(len);
-		uploadedBytes += len;
+			const bool ok = dummyUpload || fileBeingUploaded.Write(buffer, len);
+			skt->Taken(len);
+			uploadedBytes += len;
 
-		if (!ok)
-		{
-			uploadError = true;
-			GetPlatform().Message(ErrorMessage, "HTTP: could not write upload data\n");
-			CancelUpload();
-			SendJsonResponse("upload");
-			return;
-		}
+			if (!ok)
+			{
+				uploadError = true;
+				GetPlatform().Message(ErrorMessage, "HTTP: could not write upload data\n");
+				CancelUpload();
+				SendJsonResponse("upload");
+				return;
+			}
+		} while (skt->ReadBuffer(buffer, len));
 	}
 	else if (!skt->CanRead() || millis() - timer >= HttpSessionTimeout)
 	{
diff --git a/src/Networking/LwipEthernet/Lwip/lwipopts.h b/src/Networking/LwipEthernet/Lwip/lwipopts.h
index e67dcc6c..559aea5c 100644
--- a/src/Networking/LwipEthernet/Lwip/lwipopts.h
+++ b/src/Networking/LwipEthernet/Lwip/lwipopts.h
@@ -63,7 +63,7 @@
 
 /**
  * LWIP_NETIF_STATUS_CALLBACK==1: Support a callback function whenever an interface
- * changes its up/down status (i.e., due to DHCP IP acquistion)
+ * changes its up/down status (i.e., due to DHCP IP acquisition)
  */
 #define LWIP_NETIF_STATUS_CALLBACK	1
 
@@ -89,9 +89,14 @@
 
 #define LWIP_CHKSUM_ALGORITHM		3		// use fastest checksum algorithm (does 8 bytes at a time)
 
+#define CHECKSUM_CHECK_IP			0		// use hardware checking of incoming IP checksums
+#define CHECKSUM_CHECK_UDP			0		// use hardware checking of incoming UDP checksums
+#define CHECKSUM_CHECK_TCP			0		// use hardware checking of incoming TCP checksums
+
 #define LWIP_DONT_PROVIDE_BYTEORDER_FUNCTIONS	1
-#define lwip_htons(_x)		__builtin_bswap16(_x)
-#define lwip_htonl(_x)		__builtin_bswap32(_x)
+#define lwip_htons(_x)			__builtin_bswap16(_x)
+#define lwip_htonl(_x)			__builtin_bswap32(_x)
+#define SWAP_BYTES_IN_WORD(_x)	__builtin_bswap16(_x)
 
 /*
    ------------------------------------
@@ -120,7 +125,7 @@
 #define MEMP_NUM_UDP_PCB                3
 
 /**
- * MEMP_NUM_TCP_PCB: the number of simulatenously active TCP connections.
+ * MEMP_NUM_TCP_PCB: the number of simultaneously active TCP connections.
  * (requires the LWIP_TCP option)
  */
 #define MEMP_NUM_TCP_PCB                8
@@ -179,7 +184,7 @@
 /**
  * PBUF_POOL_BUFSIZE: the size of each pbuf in the pbuf pool.
  */
-#define PBUF_POOL_BUFSIZE               GMAC_FRAME_LENTGH_MAX
+#define PBUF_POOL_BUFSIZE               GMAC_FRAME_LENGTH_MAX
 
 /*
    ----------------------------------
@@ -240,7 +245,7 @@ extern uint32_t random32(void) noexcept;
  * TCP_WND: The size of a TCP window.  This must be at least
  * (2 * TCP_MSS) for things to work well
  */
-#define TCP_WND                 (2 * TCP_MSS)
+#define TCP_WND                 (4 * TCP_MSS)
 
 /**
  * TCP_SND_BUF: TCP sender buffer space (bytes).
diff --git a/src/Networking/LwipEthernet/Lwip/src/core/tcp_in.c b/src/Networking/LwipEthernet/Lwip/src/core/tcp_in.c
index 428a6f48..e198fd13 100644
--- a/src/Networking/LwipEthernet/Lwip/src/core/tcp_in.c
+++ b/src/Networking/LwipEthernet/Lwip/src/core/tcp_in.c
@@ -1645,6 +1645,7 @@ tcp_receive(struct tcp_pcb *pcb)
         /* We get here if the incoming segment is out-of-sequence. */
 
 #if TCP_QUEUE_OOSEQ
+    	//debugPrintf("OOS! have %" PRIu32 ", expected %" PRIu32 " to %" PRIu32 "\n", seqno, pcb->rcv_nxt, pcb->rcv_nxt + pcb->rcv_wnd - 1);
         /* We queue the segment on the ->ooseq queue. */
         if (pcb->ooseq == NULL) {
           pcb->ooseq = tcp_seg_copy(&inseg);
@@ -1873,6 +1874,7 @@ tcp_receive(struct tcp_pcb *pcb)
       }
     } else {
       /* The incoming segment is not within the window. */
+      //debugPrintf("Not in window: %" PRIu32 ", expected %" PRIu32 " to %" PRIu32 "\n", seqno, pcb->rcv_nxt, pcb->rcv_nxt + pcb->rcv_wnd - 1);
       tcp_send_empty_ack(pcb);
     }
   } else {
diff --git a/src/Networking/LwipEthernet/LwipEthernetInterface.cpp b/src/Networking/LwipEthernet/LwipEthernetInterface.cpp
index 443a09f7..0430a81c 100644
--- a/src/Networking/LwipEthernet/LwipEthernetInterface.cpp
+++ b/src/Networking/LwipEthernet/LwipEthernetInterface.cpp
@@ -70,15 +70,9 @@ Mutex lwipMutex;
 
 extern "C"
 {
-	// Task function to keep the GMAC and LwIP running
-	void DoEthernetTask()
-	{
-		ethernet_task();
-	}
-
 	// Callback functions for LWIP (may be called from ISR)
 	// This occasionally seems to get called with a null pcb argument, so check for that here
-	static err_t conn_accept(void *arg, tcp_pcb *pcb, err_t err)
+	static err_t conn_accept(void *arg, tcp_pcb *pcb, err_t err) noexcept
 	{
 		LWIP_UNUSED_ARG(arg);
 		LWIP_UNUSED_ARG(err);
@@ -450,7 +444,7 @@ void LwipEthernetInterface::Spin() noexcept
 		if (ethernet_link_established())
 		{
 			// Check for incoming packets
-			DoEthernetTask();
+			ethernet_task();
 
 			// Have we obtained an IP address yet?
 			ethernet_get_ipaddress(ipAddress, netmask, gateway);
@@ -483,7 +477,7 @@ void LwipEthernetInterface::Spin() noexcept
 		if (ethernet_link_established())
 		{
 			// Check for incoming packets
-			DoEthernetTask();
+			ethernet_task();
 
 			// Poll the next TCP socket
 			sockets[nextSocketToPoll]->Poll();
@@ -513,10 +507,9 @@ void LwipEthernetInterface::Spin() noexcept
 
 void LwipEthernetInterface::Diagnostics(MessageType mtype) noexcept
 {
-	platform.MessageF(mtype, "- Ethernet -\nState: %s\n", GetStateName());
-	platform.MessageF(mtype, "Error counts: %u %u %u %u %u\nSocket states:",
-								rxErrorCount, rxBuffersNotFullyPopulatedCount, txErrorCount, txBufferNotFreeCount, txBufferTooShortCount);
-	for (LwipSocket *s : sockets)
+	platform.MessageF(mtype, "= Ethernet =\nState: %s\n", GetStateName());
+	ethernetif_diagnostics(mtype);
+	for (const LwipSocket *s : sockets)
 	{
 		platform.MessageF(mtype, " %d", s->GetState());
 	}
diff --git a/src/Networking/LwipEthernet/LwipSocket.cpp b/src/Networking/LwipEthernet/LwipSocket.cpp
index fc015ba2..30fb787c 100644
--- a/src/Networking/LwipEthernet/LwipSocket.cpp
+++ b/src/Networking/LwipEthernet/LwipSocket.cpp
@@ -112,13 +112,14 @@ void LwipSocket::DataReceived(pbuf *data) noexcept
 	if (state != SocketState::closing)
 	{
 		// Store it for the NetworkResponder
-		if (receivedData == nullptr)
+		pbuf *const rdata = receivedData;
+		if (rdata == nullptr)
 		{
 			receivedData = data;
 		}
 		else
 		{
-			pbuf_cat(receivedData, data);
+			pbuf_cat(rdata, data);
 		}
 	}
 	else
@@ -256,30 +257,47 @@ bool LwipSocket::CanSend() const noexcept
 	return (state == SocketState::connected);
 }
 
+// Get the next received pbuf, skipping any empty ones (we can get empty ones from lwip)
+pbuf *LwipSocket::GetNextReceivedPbuf() noexcept
+{
+	pbuf *rdata;
+	while ((rdata = receivedData) != nullptr && rdata->len == 0)
+	{
+		debugPrintf("Discarding empty pbuf\n");
+		MutexLocker lock(lwipMutex);
+		receivedData = rdata->next;
+		rdata->next = nullptr;
+		pbuf_free(rdata);
+		readIndex = 0;
+	}
+	return rdata;
+}
+
 // Read 1 character from the receive buffers, returning true if successful
 bool LwipSocket::ReadChar(char& c) noexcept
 {
-	if (receivedData != nullptr)
+	pbuf *const rdata = GetNextReceivedPbuf();
+	if (rdata != nullptr)
 	{
-		const char * const data = (const char *)receivedData->payload;
+		const char * const data = (const char *)rdata->payload;
 		c = data[readIndex++];
 
-		if (readIndex >= receivedData->len)
+		const uint16_t rlen = rdata->len;
+		if (readIndex >= rlen)
 		{
-			// We've processed one more pbuf
+			// Free the buffer. Grab the mutex first to prevent lwip appending more data to it.
 			MutexLocker lock(lwipMutex);
 
+			receivedData = rdata->next;
+			rdata->next = nullptr;
+			pbuf_free(rdata);
+			readIndex = 0;
+
+			// Tell lwip we have taken this data
 			if (connectionPcb != nullptr)
 			{
-				tcp_recved(connectionPcb, receivedData->len);
+				tcp_recved(connectionPcb, rlen);
 			}
-
-			// Free the first item of the pbuf chain and move on to the next one
-			pbuf *currentBlock = receivedData;
-			receivedData = receivedData->next;
-			currentBlock->next = nullptr;
-			pbuf_free(currentBlock);
-			readIndex = 0;
 		}
 
 		return true;
@@ -292,11 +310,12 @@ bool LwipSocket::ReadChar(char& c) noexcept
 // Return a pointer to data in a buffer and a length available
 bool LwipSocket::ReadBuffer(const uint8_t *&buffer, size_t &len) noexcept
 {
-	if (receivedData != nullptr)
+	pbuf *const rdata = GetNextReceivedPbuf();
+	if (rdata != nullptr)
 	{
-		const uint8_t * const data = (const uint8_t *)receivedData->payload;
+		const uint8_t * const data = (const uint8_t *)rdata->payload;
 		buffer = &data[readIndex];
-		len = receivedData->len - readIndex;
+		len = rdata->len - readIndex;
 		return true;
 	}
 
@@ -306,25 +325,27 @@ bool LwipSocket::ReadBuffer(const uint8_t *&buffer, size_t &len) noexcept
 // Flag some data as taken from the receive buffers. We never take data from more than one buffer at a time.
 void LwipSocket::Taken(size_t len) noexcept
 {
-	if (receivedData != nullptr)
+	pbuf *const rdata = receivedData;
+	if (rdata != nullptr)			// should always be true
 	{
 		readIndex += len;
-		if (readIndex >= receivedData->len)
+		const uint16_t rlen = rdata->len;
+		if (readIndex >= rlen)
 		{
-			// Notify LwIP
+			// Free the buffer. Grab the mutex first to prevent lwip appending more data to it.
 			MutexLocker lock(lwipMutex);
 
+			// Free the first item of the pbuf chain if the number of taken bytes exceeds its size
+			receivedData = rdata->next;
+			rdata->next = nullptr;
+			pbuf_free(rdata);
+			readIndex = 0;
+
+			// Notify LwIP
 			if (connectionPcb != nullptr)
 			{
-				tcp_recved(connectionPcb, receivedData->len);
+				tcp_recved(connectionPcb, rlen);
 			}
-
-			// Free the first item of the pbuf chain if the number of taken bytes exceeds its size
-			pbuf *currentBlock = receivedData;
-			receivedData = receivedData->next;
-			currentBlock->next = nullptr;
-			pbuf_free(currentBlock);
-			readIndex = 0;
 		}
 	}
 }
@@ -346,8 +367,6 @@ void LwipSocket::Poll() noexcept
 		break;
 
 	case SocketState::connected:
-		// A connection has been established, but no responder has been found yet
-		// See if we can assign this socket
 		if (responderFound)
 		{
 			// Are we still waiting for data to be written?
@@ -415,13 +434,14 @@ void LwipSocket::Poll() noexcept
 	}
 }
 
-// Discard any received data for this transaction
+// Discard any received data for this transaction. Acquire the lwip mutex before calling this.
 void LwipSocket::DiscardReceivedData() noexcept
 {
-	if (receivedData != nullptr)
+	pbuf *const rdata = receivedData;
+	if (rdata != nullptr)
 	{
-		pbuf_free(receivedData);
 		receivedData = nullptr;
+		pbuf_free(rdata);
 	}
 	readIndex = 0;
 }
diff --git a/src/Networking/LwipEthernet/LwipSocket.h b/src/Networking/LwipEthernet/LwipSocket.h
index ddedf5d8..c51e250c 100644
--- a/src/Networking/LwipEthernet/LwipSocket.h
+++ b/src/Networking/LwipEthernet/LwipSocket.h
@@ -63,6 +63,7 @@ private:
 
 	void ReInit() noexcept;
 	void DiscardReceivedData() noexcept;
+	pbuf *GetNextReceivedPbuf() noexcept;
 
 	uint32_t whenConnected;
 	uint32_t whenWritten;
@@ -70,7 +71,7 @@ private:
 	bool responderFound;
 
 	tcp_pcb *connectionPcb;
-	pbuf *receivedData;
+	pbuf *volatile receivedData;
 	size_t readIndex;
 
 	SocketState state;
diff --git a/src/Networking/Network.cpp b/src/Networking/Network.cpp
index c8fd283a..cf012cc0 100644
--- a/src/Networking/Network.cpp
+++ b/src/Networking/Network.cpp
@@ -555,7 +555,11 @@ void Network::Spin() noexcept
 		{
 			slowLoop = dt;
 		}
-		RTOSIface::Yield();
+
+		if (!doneSomething)
+		{
+			RTOSIface::Yield();
+		}
 	}
 }
 #endif