i40e: Removing hung_queue variable to use txqueue function parameter

The scope of function .ndo_tx_timeout was changed to include the hang
queue when a TX timeout event occurs. See commit 0290bd29
("netdev: pass the stuck queue to the timeout handler") for more
details. Now, drivers don't need to identify which queue is stopped.
Drivers can simply use the queue index provided by dev_watchdog and
execute all actions needed to restore network traffic. This commit do
some cleanups into Intel i40e driver to remove a redundant loop to find
stopped queue.
Signed-off-by: Julio Faracco <jcfaracco@gmail.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

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

@@ -307,40 +307,21 @@ static void i40e_tx_timeout(struct net_device *netdev, unsigned int txqueue)
 	struct i40e_vsi *vsi = np->vsi;
 	struct i40e_pf *pf = vsi->back;
 	struct i40e_ring *tx_ring = NULL;
-	unsigned int i, hung_queue = 0;
+	unsigned int i;
 	u32 head, val;
 
 	pf->tx_timeout_count++;
 
-	/* find the stopped queue the same way the stack does */
-	for (i = 0; i < netdev->num_tx_queues; i++) {
-		struct netdev_queue *q;
-		unsigned long trans_start;
-
-		q = netdev_get_tx_queue(netdev, i);
-		trans_start = q->trans_start;
-		if (netif_xmit_stopped(q) &&
-		    time_after(jiffies,
-			       (trans_start + netdev->watchdog_timeo))) {
-			hung_queue = i;
-			break;
-		}
-	}
-
-	if (i == netdev->num_tx_queues) {
-		netdev_info(netdev, "tx_timeout: no netdev hung queue found\n");
-	} else {
-		/* now that we have an index, find the tx_ring struct */
+	/* with txqueue index, find the tx_ring struct */
 	for (i = 0; i < vsi->num_queue_pairs; i++) {
 		if (vsi->tx_rings[i] && vsi->tx_rings[i]->desc) {
-				if (hung_queue ==
+			if (txqueue ==
 			    vsi->tx_rings[i]->queue_index) {
 				tx_ring = vsi->tx_rings[i];
 				break;
 			}
 		}
 	}
-	}
 
 	if (time_after(jiffies, (pf->tx_timeout_last_recovery + HZ*20)))
 		pf->tx_timeout_recovery_level = 1;  /* reset after some time */
@@ -363,14 +344,14 @@ static void i40e_tx_timeout(struct net_device *netdev, unsigned int txqueue)
 			val = rd32(&pf->hw, I40E_PFINT_DYN_CTL0);
 
 		netdev_info(netdev, "tx_timeout: VSI_seid: %d, Q %d, NTC: 0x%x, HWB: 0x%x, NTU: 0x%x, TAIL: 0x%x, INT: 0x%x\n",
-			    vsi->seid, hung_queue, tx_ring->next_to_clean,
+			    vsi->seid, txqueue, tx_ring->next_to_clean,
 			    head, tx_ring->next_to_use,
 			    readl(tx_ring->tail), val);
 	}
 
 	pf->tx_timeout_last_recovery = jiffies;
-	netdev_info(netdev, "tx_timeout recovery level %d, hung_queue %d\n",
-		    pf->tx_timeout_recovery_level, hung_queue);
+	netdev_info(netdev, "tx_timeout recovery level %d, txqueue %d\n",
+		    pf->tx_timeout_recovery_level, txqueue);
 
 	switch (pf->tx_timeout_recovery_level) {
 	case 1: