Aw: [PATCH 1/1] ixgbe: write flush vfta registers

Sometimes vfta registers can not be written successfully in dcb mode.
This is very occassional. When the ixgbe nic runs for a very long time,
sometimes this bug occurs. But after IXGBE_WRITE_FLUSH is executed,
this bug never occurs.

Signed-off-by: Zhu Yanjun <zyjzyj2000@gmail.com>
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index bd93d82..1221cfb 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c

@@ -4138,8 +4138,10 @@ static void ixgbe_vlan_promisc_enable(struct ixgbe_adapter *adapter)
 	}
 
 	/* Set all bits in the VLAN filter table array */
-	for (i = hw->mac.vft_size; i--;)
+	for (i = hw->mac.vft_size; i--;) {
 		IXGBE_WRITE_REG(hw, IXGBE_VFTA(i), ~0U);
+		IXGBE_WRITE_FLUSH(hw);
+	}