ixgbe: fix ixgbe_tx_is_paused logic

The TFCS bits show the current XON state.  Meaning that the
device is paused if these bits are 0.  This fixes the logic
to work as it was intended.
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ixgbe/ixgbe_main.c

@@ -625,16 +625,16 @@ static void ixgbe_unmap_and_free_tx_resource(struct ixgbe_adapter *adapter,
 }
 
 /**
- * ixgbe_tx_is_paused - check if the tx ring is paused
+ * ixgbe_tx_xon_state - check the tx ring xon state
  * @adapter: the ixgbe adapter
  * @tx_ring: the corresponding tx_ring
  *
  * If not in DCB mode, checks TFCS.TXOFF, otherwise, find out the
  * corresponding TC of this tx_ring when checking TFCS.
  *
- * Returns : true if paused
+ * Returns : true if in xon state (currently not paused)
  */
-static inline bool ixgbe_tx_is_paused(struct ixgbe_adapter *adapter,
+static inline bool ixgbe_tx_xon_state(struct ixgbe_adapter *adapter,
                                       struct ixgbe_ring *tx_ring)
 {
 	u32 txoff = IXGBE_TFCS_TXOFF;
@@ -690,7 +690,7 @@ static inline bool ixgbe_check_tx_hang(struct ixgbe_adapter *adapter,
 	adapter->detect_tx_hung = false;
 	if (tx_ring->tx_buffer_info[eop].time_stamp &&
 	    time_after(jiffies, tx_ring->tx_buffer_info[eop].time_stamp + HZ) &&
-	    !ixgbe_tx_is_paused(adapter, tx_ring)) {
+	    ixgbe_tx_xon_state(adapter, tx_ring)) {
 		/* detected Tx unit hang */
 		union ixgbe_adv_tx_desc *tx_desc;
 		tx_desc = IXGBE_TX_DESC_ADV(*tx_ring, eop);