[PATCH iwl-next] ixgbe: call ixgbe_setup_fc() before fc_enable() after NVM update

[Aleksandr Loktionov <aleksandr.loktionov@intel.com>]

From: Radoslaw Tyl <radoslawx.tyl@intel.com>

During an NVM update the PHY reset clears the Technology Ability Field
(IEEE 802.3 clause 37 register 7.10) back to hardware defaults.  When
the driver subsequently calls only hw->mac.ops.fc_enable() the SRRCTL
register is recalculated from the stale autonegotiated capability bits,
which the MDD (Malicious Driver Detect) logic treats as an invalid
change and halts traffic on the PF.

Fix by calling ixgbe_setup_fc() immediately before fc_enable() in
ixgbe_watchdog_update_link() so that flow-control autoneg and the
PHY registers are re-programmed in the correct order after any reset.

Signed-off-by: Radoslaw Tyl <radoslawx.tyl@intel.com>
Signed-off-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 52f0cdc..db954e9 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -8041,6 +8041,12 @@ static void ixgbe_watchdog_update_link(struct ixgbe_adapter *adapter)
 		pfc_en |= !!(adapter->ixgbe_ieee_pfc->pfc_en);
 
 	if (link_up && !((adapter->flags & IXGBE_FLAG_DCB_ENABLED) && pfc_en)) {
+		if (hw->mac.ops.setup_fc) {
+			int err = hw->mac.ops.setup_fc(hw);
+
+			if (err)
+				e_warn(drv, "setup_fc failed: %d\n", err);
+		}
 		hw->mac.ops.fc_enable(hw);
 		ixgbe_set_rx_drop_en(adapter);
 	}
-- 
2.52.0