netdev - [PATCH net-next 1/2] drivers: net: i40e: Removing hung_queue variable to use txqueue function parameter

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Message-Id: <20191218183845.20038-2-jcfaracco@gmail.com>
Date:   Wed, 18 Dec 2019 15:38:44 -0300
From:   Julio Faracco <jcfaracco@...il.com>
To:     netdev@...r.kernel.org
Cc:     jeffrey.t.kirsher@...el.com, davem@...emloft.net,
        intel-wired-lan@...ts.osuosl.org
Subject: [PATCH net-next 1/2] drivers: net: 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 0290bd291cc0
("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 bt 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@...il.com>
---
 drivers/net/ethernet/intel/i40e/i40e_main.c | 41 ++++++---------------
 1 file changed, 11 insertions(+), 30 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 4c9ac6c80eb8..71fedee21488 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -307,37 +307,18 @@ 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 */
-		for (i = 0; i < vsi->num_queue_pairs; i++) {
-			if (vsi->tx_rings[i] && vsi->tx_rings[i]->desc) {
-				if (hung_queue ==
-				    vsi->tx_rings[i]->queue_index) {
-					tx_ring = vsi->tx_rings[i];
-					break;
-				}
+	/* 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 (txqueue ==
+			    vsi->tx_rings[i]->queue_index) {
+				tx_ring = vsi->tx_rings[i];
+				break;
 			}
 		}
 	}
@@ -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:
-- 
2.17.1