i40e: Prevent link flow control settings when PFC is enabled

When PFC is enabled we should not proceed with setting the link flow control
parameters.  Also, always report the link flow Tx/Rx settings as off when
PFC is enabled.

Change-ID: Ib09ec58afdf0b2e587ac9d8851a5c80ad58206c4
Signed-off-by: NNeerav Parikh <neerav.parikh@intel.com>
Tested-By: NJack Morgan <jack.morgan@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e_ethtool.c

@@ -644,11 +644,19 @@ static void i40e_get_pauseparam(struct net_device *netdev,
 	struct i40e_pf *pf = np->vsi->back;
 	struct i40e_hw *hw = &pf->hw;
 	struct i40e_link_status *hw_link_info = &hw->phy.link_info;
+	struct i40e_dcbx_config *dcbx_cfg = &hw->local_dcbx_config;
 
 	pause->autoneg =
 		((hw_link_info->an_info & I40E_AQ_AN_COMPLETED) ?
 		  AUTONEG_ENABLE : AUTONEG_DISABLE);
 
+	/* PFC enabled so report LFC as off */
+	if (dcbx_cfg->pfc.pfcenable) {
+		pause->rx_pause = 0;
+		pause->tx_pause = 0;
+		return;
+	}
+
 	if (hw->fc.current_mode == I40E_FC_RX_PAUSE) {
 		pause->rx_pause = 1;
 	} else if (hw->fc.current_mode == I40E_FC_TX_PAUSE) {
@@ -672,6 +680,7 @@ static int i40e_set_pauseparam(struct net_device *netdev,
 	struct i40e_vsi *vsi = np->vsi;
 	struct i40e_hw *hw = &pf->hw;
 	struct i40e_link_status *hw_link_info = &hw->phy.link_info;
+	struct i40e_dcbx_config *dcbx_cfg = &hw->local_dcbx_config;
 	bool link_up = hw_link_info->link_info & I40E_AQ_LINK_UP;
 	i40e_status status;
 	u8 aq_failures;
@@ -693,8 +702,9 @@ static int i40e_set_pauseparam(struct net_device *netdev,
 		netdev_info(netdev, "Autoneg did not complete so changing settings may not result in an actual change.\n");
 	}
 
-	if (hw->fc.current_mode == I40E_FC_PFC) {
-		netdev_info(netdev, "Priority flow control enabled. Cannot set link flow control.\n");
+	if (dcbx_cfg->pfc.pfcenable) {
+		netdev_info(netdev,
+			    "Priority flow control enabled. Cannot set link flow control.\n");
 		return -EOPNOTSUPP;
 	}