[RESEND][PATCH net-drivers-2.6 6/16] e1000: Delay clean-up of last Tx packet (fwd)

Delay clean-up of last Tx packet to fix pre-mature writeback issue of Tx descriptors only when TSO is enabled

Signed-off-by: Mallikarjuna R Chilakala <redacted>
Signed-off-by: Ganesh Venkatesan <redacted>
Signed-off-by: John Ronciak <redacted>

diff -up net-drivers-2.6/drivers/net/e1000/e1000_main.c net-drivers-2.6/drivers/net/e1000.new/e1000_main.c

--- net-drivers-2.6/drivers/net/e1000/e1000_main.c      2005-04-11 02:22:27.000000000 -0700
+++ net-drivers-2.6/drivers/net/e1000.new/e1000_main.c  2005-04-11 02:22:29.000000000 -0700

@@ -2384,11 +2384,10 @@ e1000_clean_tx_irq(struct e1000_adapter

        eop_desc = E1000_TX_DESC(*tx_ring, eop);
 
        while(eop_desc->upper.data & cpu_to_le32(E1000_TXD_STAT_DD)) {
-               /* pre-mature writeback of Tx descriptors     */
-               /* clear (free buffers and unmap pci_mapping) */
-               /* previous_buffer_info                       */
+               /* Premature writeback of Tx descriptors clear (free buffers
+                * and unmap pci_mapping) previous_buffer_info */
                if (likely(adapter->previous_buffer_info.skb != NULL)) {
-                       e1000_unmap_and_free_tx_resource(adapter,
+                       e1000_unmap_and_free_tx_resource(adapter,
                                        &adapter->previous_buffer_info);
                }
 

@@ -2397,20 +2725,25 @@ e1000_clean_tx_irq(struct e1000_adapter

                        buffer_info = &tx_ring->buffer_info[i];
                        cleaned = (i == eop);
 
-                       /* pre-mature writeback of Tx descriptors */
-                       /* save the cleaning of the this for the  */
-                       /* next iteration                         */
-                       if (cleaned) {
-                               memcpy(&adapter->previous_buffer_info,
-                                       buffer_info,
-                                       sizeof(struct e1000_buffer));
-                               memset(buffer_info,
-                                       0,
-                                       sizeof(struct e1000_buffer));
+#ifdef NETIF_F_TSO
+                       if (!(netdev->features & NETIF_F_TSO)) {
+#endif
+                               e1000_unmap_and_free_tx_resource(adapter,
+                                                                buffer_info);
+#ifdef NETIF_F_TSO
                        } else {
-                               e1000_unmap_and_free_tx_resource(adapter,
-                                                       buffer_info);
+                               if (cleaned) {
+                                       memcpy(&adapter->previous_buffer_info,
+                                              buffer_info,
+                                              sizeof(struct e1000_buffer));
+                                       memset(buffer_info, 0,
+                                              sizeof(struct e1000_buffer));
+                               } else {
+                                       e1000_unmap_and_free_tx_resource(
+                                           adapter, buffer_info);
+                               }
                        }
+#endif
 
                        tx_desc->buffer_addr = 0;
                        tx_desc->lower.data = 0;

@@ -2443,7 +2760,14 @@ e1000_clean_tx_irq(struct e1000_adapter

                   !(E1000_READ_REG(&adapter->hw, STATUS) & E1000_STATUS_TXOFF))
                        netif_stop_queue(netdev);
        }
+#ifdef NETIF_F_TSO
+
+       if( unlikely(!(eop_desc->upper.data & cpu_to_le32(E1000_TXD_STAT_DD)) &&
+           time_after(jiffies, adapter->previous_buffer_info.time_stamp + HZ)))
+               e1000_unmap_and_free_tx_resource(
+                   adapter, &adapter->previous_buffer_info);
 
+#endif
        return cleaned;
 }