ixgbe: Fix 82599 adapter link flickering issues

Fix autoneg restart issues in flow control path which might create
endless link flickering due to known timing issues with 82599
adapters.

Signed-off-by: Mallikarjuna R Chilakala <mallikarjuna.chilakakla@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 20 insertions, 8 deletions

diff --git a/drivers/net/ixgbe/ixgbe_ethtool.c b/drivers/net/ixgbe/ixgbe_ethtool.c
index 583cc5a3c4f9..1c110459d33b 100644
--- a/drivers/net/ixgbe/ixgbe_ethtool.c
+++ b/drivers/net/ixgbe/ixgbe_ethtool.c
@@ -283,6 +283,7 @@ static int ixgbe_set_pauseparam(struct net_device *netdev,
 {
         struct ixgbe_adapter *adapter = netdev_priv(netdev);
         struct ixgbe_hw *hw = &adapter->hw;
+        struct ixgbe_fc_info fc;
 
 #ifdef CONFIG_DCB
         if (adapter->dcb_cfg.pfc_mode_enable ||
@@ -291,26 +292,37 @@ static int ixgbe_set_pauseparam(struct net_device *netdev,
                 return -EINVAL;
 
 #endif
+
+        fc = hw->fc;
+
         if (pause->autoneg != AUTONEG_ENABLE)
-                hw->fc.disable_fc_autoneg = true;
+                fc.disable_fc_autoneg = true;
         else
-                hw->fc.disable_fc_autoneg = false;
+                fc.disable_fc_autoneg = false;
 
         if (pause->rx_pause && pause->tx_pause)
-                hw->fc.requested_mode = ixgbe_fc_full;
+                fc.requested_mode = ixgbe_fc_full;
         else if (pause->rx_pause && !pause->tx_pause)
-                hw->fc.requested_mode = ixgbe_fc_rx_pause;
+                fc.requested_mode = ixgbe_fc_rx_pause;
         else if (!pause->rx_pause && pause->tx_pause)
-                hw->fc.requested_mode = ixgbe_fc_tx_pause;
+                fc.requested_mode = ixgbe_fc_tx_pause;
         else if (!pause->rx_pause && !pause->tx_pause)
-                hw->fc.requested_mode = ixgbe_fc_none;
+                fc.requested_mode = ixgbe_fc_none;
         else
                 return -EINVAL;
 
 #ifdef CONFIG_DCB
-        adapter->last_lfc_mode = hw->fc.requested_mode;
+        adapter->last_lfc_mode = fc.requested_mode;
 #endif
-        hw->mac.ops.setup_fc(hw, 0);
+
+        /* if the thing changed then we'll update and use new autoneg */
+        if (memcmp(&fc, &hw->fc, sizeof(struct ixgbe_fc_info))) {
+                hw->fc = fc;
+                if (netif_running(netdev))
+                        ixgbe_reinit_locked(adapter);
+                else
+                        ixgbe_reset(adapter);
+        }
 
         return 0;
 }