[PATCH] e1000:Adjust flow control watermarks for Jumbo Frames

Adjust flow control watermarks for Jumbo Frames

Signed-off-by: Mallikarjuna R Chilakala <mallikarjuna.chilakala@intel.com>
Signed-off-by: Ganesh Venkatesan <ganesh.venkatesan@intel.com>
Signed-off-by: John Ronciak <john.ronciak@intel.com>
diff -up net-drivers-2.6/drivers/net/e1000/e1000_main.c net-drivers-2.6/drivers/net/e1000.new/e1000_main.c

1 files changed, 15 insertions, 2 deletions

diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c
index 13bde9090537..24d96c02b509 100644
--- a/drivers/net/e1000/e1000_main.c
+++ b/drivers/net/e1000/e1000_main.c
@@ -409,7 +409,10 @@ e1000_down(struct e1000_adapter *adapter)
 void
 e1000_reset(struct e1000_adapter *adapter)
 {
+        struct net_device *netdev = adapter->netdev;
         uint32_t pba, manc;
+        uint16_t fc_high_water_mark = E1000_FC_HIGH_DIFF;
+        uint16_t fc_low_water_mark = E1000_FC_LOW_DIFF;
 
         /* Repartition Pba for greater than 9k mtu
          * To take effect CTRL.RST is required.
@@ -428,6 +431,16 @@ e1000_reset(struct e1000_adapter *adapter)
                 break;
         }
 
+        if((adapter->hw.mac_type != e1000_82573) &&
+           (adapter->rx_buffer_len > E1000_RXBUFFER_8192)) {
+                pba -= 8; /* allocate more FIFO for Tx */
+                /* send an XOFF when there is enough space in the
+                 * Rx FIFO to hold one extra full size Rx packet 
+                */
+                fc_high_water_mark = netdev->mtu + ENET_HEADER_SIZE + 
+                                        ETHERNET_FCS_SIZE + 1;
+                fc_low_water_mark = fc_high_water_mark + 8;
+        }
 
 
         if(adapter->hw.mac_type == e1000_82547) {
@@ -442,9 +455,9 @@ e1000_reset(struct e1000_adapter *adapter)
 
         /* flow control settings */
         adapter->hw.fc_high_water = (pba << E1000_PBA_BYTES_SHIFT) -
-                                    E1000_FC_HIGH_DIFF;
+                                    fc_high_water_mark;
         adapter->hw.fc_low_water = (pba << E1000_PBA_BYTES_SHIFT) -
-                                   E1000_FC_LOW_DIFF;
+                                   fc_low_water_mark;
         adapter->hw.fc_pause_time = E1000_FC_PAUSE_TIME;
         adapter->hw.fc_send_xon = 1;
         adapter->hw.fc = adapter->hw.original_fc;