[PATCH] TSO fix

* Premature write-back of descriptors during TSO causing
  resources to be returned too early on ppc64.  Fix is to
  wait until last descriptor of frame is written back,
  then return resources back to OS.
* 82544 hang caused by setting RS bit in context descriptor.
  Exposes known hang in 82544.  Fix is same as above - set
  RS bit only in last descriptor.

drivers/net/e1000/e1000.h

@@ -134,6 +134,7 @@ struct e1000_buffer {
 	uint64_t dma;
 	unsigned long length;
 	unsigned long time_stamp;
+	unsigned int next_to_watch;
 };
 
 struct e1000_desc_ring {

drivers/net/e1000/e1000_main.c

@@ -831,8 +831,9 @@ e1000_configure_tx(struct e1000_adapter *adapter)
 
 	e1000_config_collision_dist(&adapter->hw);
 
-	/* Setup Transmit Descriptor Settings for this adapter */
-	adapter->txd_cmd = E1000_TXD_CMD_IFCS | E1000_TXD_CMD_IDE;
+	/* Setup Transmit Descriptor Settings for eop descriptor */
+	adapter->txd_cmd = E1000_TXD_CMD_IDE | E1000_TXD_CMD_EOP |
+		E1000_TXD_CMD_IFCS;
 
 	if(adapter->hw.report_tx_early == 1)
 		adapter->txd_cmd |= E1000_TXD_CMD_RS;
@@ -1435,7 +1436,7 @@ e1000_watchdog(unsigned long data)
 #define E1000_TX_FLAGS_VLAN_SHIFT	16
 
 static inline boolean_t
-e1000_tso(struct e1000_adapter *adapter, struct sk_buff *skb, int tx_flags)
+e1000_tso(struct e1000_adapter *adapter, struct sk_buff *skb)
 {
 #ifdef NETIF_F_TSO
 	struct e1000_context_desc *context_desc;
@@ -1471,7 +1472,7 @@ e1000_tso(struct e1000_adapter *adapter, struct sk_buff *skb, int tx_flags)
 		context_desc->upper_setup.tcp_fields.tucse = cpu_to_le16(tucse);
 		context_desc->tcp_seg_setup.fields.mss     = cpu_to_le16(mss);
 		context_desc->tcp_seg_setup.fields.hdr_len = hdr_len;
-		context_desc->cmd_and_length = cpu_to_le32(adapter->txd_cmd |
+		context_desc->cmd_and_length = cpu_to_le32(
 			E1000_TXD_CMD_DEXT | E1000_TXD_CMD_TSE |
 			E1000_TXD_CMD_IP | E1000_TXD_CMD_TCP |
 			(skb->len - (hdr_len)));
@@ -1504,8 +1505,7 @@ e1000_tx_csum(struct e1000_adapter *adapter, struct sk_buff *skb)
 		context_desc->upper_setup.tcp_fields.tucso = cso;
 		context_desc->upper_setup.tcp_fields.tucse = 0;
 		context_desc->tcp_seg_setup.data = 0;
-		context_desc->cmd_and_length =
-			cpu_to_le32(adapter->txd_cmd | E1000_TXD_CMD_DEXT);
+		context_desc->cmd_and_length = cpu_to_le32(E1000_TXD_CMD_DEXT);
 
 		if(++i == adapter->tx_ring.count) i = 0;
 		adapter->tx_ring.next_to_use = i;
@@ -1520,7 +1520,8 @@ e1000_tx_csum(struct e1000_adapter *adapter, struct sk_buff *skb)
 #define E1000_MAX_DATA_PER_TXD	(1<<E1000_MAX_TXD_PWR)
 
 static inline int
-e1000_tx_map(struct e1000_adapter *adapter, struct sk_buff *skb)
+e1000_tx_map(struct e1000_adapter *adapter, struct sk_buff *skb,
+	unsigned int first)
 {
 	struct e1000_desc_ring *tx_ring = &adapter->tx_ring;
 	int len = skb->len, offset = 0, size, count = 0, i;
@@ -1588,6 +1589,7 @@ e1000_tx_map(struct e1000_adapter *adapter, struct sk_buff *skb)
 	}
 	if(--i < 0) i = tx_ring->count - 1;
 	tx_ring->buffer_info[i].skb = skb;
+	tx_ring->buffer_info[first].next_to_watch = i;
 
 	return count;
 }
@@ -1597,12 +1599,9 @@ e1000_tx_queue(struct e1000_adapter *adapter, int count, int tx_flags)
 {
 	struct e1000_desc_ring *tx_ring = &adapter->tx_ring;
 	struct e1000_tx_desc *tx_desc = NULL;
-	uint32_t txd_upper, txd_lower;
+	uint32_t txd_upper = 0, txd_lower = E1000_TXD_CMD_IFCS;
 	int i;
 
-	txd_upper = 0;
-	txd_lower = adapter->txd_cmd;
-
 	if(tx_flags & E1000_TX_FLAGS_TSO) {
 		txd_lower |= E1000_TXD_CMD_DEXT | E1000_TXD_DTYP_D |
 		             E1000_TXD_CMD_TSE;
@@ -1630,7 +1629,7 @@ e1000_tx_queue(struct e1000_adapter *adapter, int count, int tx_flags)
 		if(++i == tx_ring->count) i = 0;
 	}
 
-	tx_desc->lower.data |= cpu_to_le32(E1000_TXD_CMD_EOP);
+	tx_desc->lower.data |= cpu_to_le32(adapter->txd_cmd);
 
 	/* Force memory writes to complete before letting h/w
 	 * know there are new descriptors to fetch.  (Only
@@ -1690,6 +1689,7 @@ static int
 e1000_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
 {
 	struct e1000_adapter *adapter = netdev->priv;
+	unsigned int first;
 	int tx_flags = 0;
 
 	if(skb->len <= 0) {
@@ -1715,12 +1715,14 @@ e1000_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
 		tx_flags |= (vlan_tx_tag_get(skb) << E1000_TX_FLAGS_VLAN_SHIFT);
 	}
 
-	if(e1000_tso(adapter, skb, tx_flags))
+	first = adapter->tx_ring.next_to_use;
+	
+	if(e1000_tso(adapter, skb))
 		tx_flags |= E1000_TX_FLAGS_TSO;
 	else if(e1000_tx_csum(adapter, skb))
 		tx_flags |= E1000_TX_FLAGS_CSUM;
 
-	e1000_tx_queue(adapter, e1000_tx_map(adapter, skb), tx_flags);
+	e1000_tx_queue(adapter, e1000_tx_map(adapter, skb, first), tx_flags);
 
 	netdev->trans_start = jiffies;
 
@@ -2069,39 +2071,47 @@ e1000_clean_tx_irq(struct e1000_adapter *adapter)
 	struct e1000_desc_ring *tx_ring = &adapter->tx_ring;
 	struct net_device *netdev = adapter->netdev;
 	struct pci_dev *pdev = adapter->pdev;
-	struct e1000_tx_desc *tx_desc;
-	int i, cleaned = FALSE;
+	struct e1000_tx_desc *tx_desc, *eop_desc;
+	struct e1000_buffer *buffer_info;
+	int i, eop, cleaned = FALSE;
 
 	i = tx_ring->next_to_clean;
-	tx_desc = E1000_TX_DESC(*tx_ring, i);
+	eop = tx_ring->buffer_info[i].next_to_watch;
+	eop_desc = E1000_TX_DESC(*tx_ring, eop);
 
-	while(tx_desc->upper.data & cpu_to_le32(E1000_TXD_STAT_DD)) {
+	while(eop_desc->upper.data & cpu_to_le32(E1000_TXD_STAT_DD)) {
 
-		cleaned = TRUE;
+		for(cleaned = FALSE; !cleaned; ) {
+			tx_desc = E1000_TX_DESC(*tx_ring, i);
+			buffer_info = &tx_ring->buffer_info[i];
 
-		if(tx_ring->buffer_info[i].dma) {
+			if(buffer_info->dma) {
 
 				pci_unmap_page(pdev,
-			               tx_ring->buffer_info[i].dma,
-			               tx_ring->buffer_info[i].length,
+					       buffer_info->dma,
+					       buffer_info->length,
 					       PCI_DMA_TODEVICE);
 
-			tx_ring->buffer_info[i].dma = 0;
+				buffer_info->dma = 0;
 			}
 
-		if(tx_ring->buffer_info[i].skb) {
+			if(buffer_info->skb) {
 
-			dev_kfree_skb_any(tx_ring->buffer_info[i].skb);
+				dev_kfree_skb_any(buffer_info->skb);
 
-			tx_ring->buffer_info[i].skb = NULL;
+				buffer_info->skb = NULL;
 			}
 
 			tx_desc->buffer_addr = 0;
 			tx_desc->lower.data = 0;
 			tx_desc->upper.data = 0;
 
+			cleaned = (i == eop);
 			if(++i == tx_ring->count) i = 0;
-		tx_desc = E1000_TX_DESC(*tx_ring, i);
+		}
+		
+		eop = tx_ring->buffer_info[i].next_to_watch;
+		eop_desc = E1000_TX_DESC(*tx_ring, eop);
 	}
 
 	tx_ring->next_to_clean = i;