i40e: fix XPS mask when resetting

During resets (possibly caused by a Tx hang) the driver would
accidentally clear the XPS mask for all queues back to 0.

This caused higher CPU utilization and had some other performance impacts
for transmit tests.

Change-ID: I95f112432c9e643a153eaa31cd28cdcbfdd01831
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e_main.c

@@ -2399,21 +2399,21 @@ static void i40e_config_xps_tx_ring(struct i40e_ring *ring)
 	struct i40e_vsi *vsi = ring->vsi;
 	cpumask_var_t mask;
 
-	if (ring->q_vector && ring->netdev) {
+	if (!ring->q_vector || !ring->netdev)
+		return;
+
 	/* Single TC mode enable XPS */
-		if (vsi->tc_config.numtc <= 1 &&
-		    !test_and_set_bit(__I40E_TX_XPS_INIT_DONE, &ring->state)) {
+	if (vsi->tc_config.numtc <= 1) {
+		if (!test_and_set_bit(__I40E_TX_XPS_INIT_DONE, &ring->state))
 			netif_set_xps_queue(ring->netdev,
 					    &ring->q_vector->affinity_mask,
 					    ring->queue_index);
 	} else if (alloc_cpumask_var(&mask, GFP_KERNEL)) {
 		/* Disable XPS to allow selection based on TC */
 		bitmap_zero(cpumask_bits(mask), nr_cpumask_bits);
-			netif_set_xps_queue(ring->netdev, mask,
-					    ring->queue_index);
+		netif_set_xps_queue(ring->netdev, mask, ring->queue_index);
 		free_cpumask_var(mask);
 	}
-	}
 }
 
 /**