amd-xgbe: Add support for the netdev Tx watchdog

Add support to be able to detect a hung Tx task by adding the netdev
ndo_tx_timeout function callback. Do not set the watchdog_timeo value
so as to use the system default time (currently 5 seconds).
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/amd/xgbe/xgbe-drv.c

@@ -1600,6 +1600,14 @@ static int xgbe_change_mtu(struct net_device *netdev, int mtu)
 	return 0;
 }
 
+static void xgbe_tx_timeout(struct net_device *netdev)
+{
+	struct xgbe_prv_data *pdata = netdev_priv(netdev);
+
+	netdev_warn(netdev, "tx timeout, device restarting\n");
+	schedule_work(&pdata->restart_work);
+}
+
 static struct rtnl_link_stats64 *xgbe_get_stats64(struct net_device *netdev,
 						  struct rtnl_link_stats64 *s)
 {
@@ -1764,6 +1772,7 @@ static const struct net_device_ops xgbe_netdev_ops = {
 	.ndo_validate_addr	= eth_validate_addr,
 	.ndo_do_ioctl		= xgbe_ioctl,
 	.ndo_change_mtu		= xgbe_change_mtu,
+	.ndo_tx_timeout		= xgbe_tx_timeout,
 	.ndo_get_stats64	= xgbe_get_stats64,
 	.ndo_vlan_rx_add_vid	= xgbe_vlan_rx_add_vid,
 	.ndo_vlan_rx_kill_vid	= xgbe_vlan_rx_kill_vid,

drivers/net/ethernet/amd/xgbe/xgbe-main.c

@@ -491,6 +491,9 @@ static int xgbe_probe(struct platform_device *pdev)
 
 	netdev->priv_flags |= IFF_UNICAST_FLT;
 
+	/* Use default watchdog timeout */
+	netdev->watchdog_timeo = 0;
+
 	xgbe_init_rx_coalesce(pdata);
 	xgbe_init_tx_coalesce(pdata);