[dpdk-dev] [PATCH] net/mlx5: fix handling link status change event

[Yongseok Koh <yskoh@mellanox.com>]

Even though link of a port gets down, device still can receive traffic.
That is the reason why mlx5_set_link_up/down() switches rx/tx_pkt_burst().
However, if link gets down by an external command (e.g. ifconfig), it isn't
effective. It is better to change burst functions when link status change
is detected.

Fixes: 62072098b54e ("mlx5: support setting link up or down")
Cc: stable@dpdk.org

Signed-off-by: Yongseok Koh <yskoh@mellanox.com>
---
 drivers/net/mlx5/mlx5.c         |   1 -
 drivers/net/mlx5/mlx5.h         |   1 +
 drivers/net/mlx5/mlx5_ethdev.c  | 112 +++++++++++++++++++++++++++++++---------
 drivers/net/mlx5/mlx5_trigger.c |  23 ++-------
 4 files changed, 93 insertions(+), 44 deletions(-)

diff --git a/drivers/net/mlx5/mlx5.c b/drivers/net/mlx5/mlx5.c
index 1c95f3520..fc2d59fee 100644
--- a/drivers/net/mlx5/mlx5.c
+++ b/drivers/net/mlx5/mlx5.c
@@ -869,7 +869,6 @@ mlx5_pci_probe(struct rte_pci_driver *pci_drv, struct rte_pci_device *pci_dev)
 		/* Bring Ethernet device up. */
 		DEBUG("forcing Ethernet interface up");
 		priv_set_flags(priv, ~IFF_UP, IFF_UP);
-		mlx5_link_update(priv->dev, 1);
 		/* Store device configuration on private structure. */
 		priv->config = config;
 		continue;
diff --git a/drivers/net/mlx5/mlx5.h b/drivers/net/mlx5/mlx5.h
index e740a4e77..9a4a59bd4 100644
--- a/drivers/net/mlx5/mlx5.h
+++ b/drivers/net/mlx5/mlx5.h
@@ -225,6 +225,7 @@ int priv_set_flags(struct priv *, unsigned int, unsigned int);
 int mlx5_dev_configure(struct rte_eth_dev *);
 void mlx5_dev_infos_get(struct rte_eth_dev *, struct rte_eth_dev_info *);
 const uint32_t *mlx5_dev_supported_ptypes_get(struct rte_eth_dev *dev);
+int priv_link_update(struct priv *, int);
 int mlx5_link_update(struct rte_eth_dev *, int);
 int mlx5_dev_set_mtu(struct rte_eth_dev *, uint16_t);
 int mlx5_dev_get_flow_ctrl(struct rte_eth_dev *, struct rte_eth_fc_conf *);
diff --git a/drivers/net/mlx5/mlx5_ethdev.c b/drivers/net/mlx5/mlx5_ethdev.c
index 6f78adc4a..16377a8cb 100644
--- a/drivers/net/mlx5/mlx5_ethdev.c
+++ b/drivers/net/mlx5/mlx5_ethdev.c
@@ -885,7 +885,49 @@ mlx5_link_update_unlocked_gs(struct rte_eth_dev *dev, int wait_to_complete)
 }
 
 /**
- * DPDK callback to retrieve physical link information.
+ * Enable receiving and transmitting traffic.
+ *
+ * @param dev
+ *   Pointer to Ethernet device structure.
+ */
+static void
+priv_link_start(struct priv *priv)
+{
+	struct rte_eth_dev *dev = priv->dev;
+	int err;
+
+	dev->tx_pkt_burst = priv_select_tx_function(priv, dev);
+	dev->rx_pkt_burst = priv_select_rx_function(priv, dev);
+	err = priv_dev_traffic_enable(priv, dev);
+	if (err)
+		ERROR("%p: error occurred while configuring control flows: %s",
+		      (void *)priv, strerror(err));
+	err = priv_flow_start(priv, &priv->flows);
+	if (err)
+		ERROR("%p: error occurred while configuring flows: %s",
+		      (void *)priv, strerror(err));
+}
+
+/**
+ * Disable receiving and transmitting traffic.
+ *
+ * @param dev
+ *   Pointer to Ethernet device structure.
+ */
+static void
+priv_link_stop(struct priv *priv)
+{
+	struct rte_eth_dev *dev = priv->dev;
+
+	priv_flow_stop(priv, &priv->flows);
+	priv_dev_traffic_disable(priv, dev);
+	dev->rx_pkt_burst = removed_rx_burst;
+	dev->tx_pkt_burst = removed_tx_burst;
+}
+
+/**
+ * Retrieve physical link information and update rx/tx_pkt_burst callbacks
+ * accordingly.
  *
  * @param dev
  *   Pointer to Ethernet device structure.
@@ -893,17 +935,54 @@ mlx5_link_update_unlocked_gs(struct rte_eth_dev *dev, int wait_to_complete)
  *   Wait for request completion (ignored).
  */
 int
-mlx5_link_update(struct rte_eth_dev *dev, int wait_to_complete)
+priv_link_update(struct priv *priv, int wait_to_complete)
 {
+	struct rte_eth_dev *dev = priv->dev;
 	struct utsname utsname;
 	int ver[3];
+	int ret;
+	struct rte_eth_link dev_link = dev->data->dev_link;
 
 	if (uname(&utsname) == -1 ||
 	    sscanf(utsname.release, "%d.%d.%d",
 		   &ver[0], &ver[1], &ver[2]) != 3 ||
 	    KERNEL_VERSION(ver[0], ver[1], ver[2]) < KERNEL_VERSION(4, 9, 0))
-		return mlx5_link_update_unlocked_gset(dev, wait_to_complete);
-	return mlx5_link_update_unlocked_gs(dev, wait_to_complete);
+		ret = mlx5_link_update_unlocked_gset(dev, wait_to_complete);
+	else
+		ret = mlx5_link_update_unlocked_gs(dev, wait_to_complete);
+	/* If lsc interrupt is disabled, should always be ready for traffic. */
+	if (!dev->data->dev_conf.intr_conf.lsc) {
+		priv_link_start(priv);
+		return ret;
+	}
+	/* Re-select burst callbacks only if link status has been changed. */
+	if (!ret && dev_link.link_status != dev->data->dev_link.link_status) {
+		if (dev->data->dev_link.link_status == ETH_LINK_UP)
+			priv_link_start(priv);
+		else
+			priv_link_stop(priv);
+	}
+	return ret;
+}
+
+/**
+ * DPDK callback to retrieve physical link information.
+ *
+ * @param dev
+ *   Pointer to Ethernet device structure.
+ * @param wait_to_complete
+ *   Wait for request completion (ignored).
+ */
+int
+mlx5_link_update(struct rte_eth_dev *dev, int wait_to_complete)
+{
+	struct priv *priv = dev->data->dev_private;
+	int ret;
+
+	priv_lock(priv);
+	ret = priv_link_update(priv, wait_to_complete);
+	priv_unlock(priv);
+	return ret;
 }
 
 /**
@@ -1113,7 +1192,7 @@ priv_link_status_update(struct priv *priv)
 {
 	struct rte_eth_link *link = &priv->dev->data->dev_link;
 
-	mlx5_link_update(priv->dev, 0);
+	priv_link_update(priv, 0);
 	if (((link->link_speed == 0) && link->link_status) ||
 		((link->link_speed != 0) && !link->link_status)) {
 		/*
@@ -1321,24 +1400,9 @@ priv_dev_interrupt_handler_install(struct priv *priv, struct rte_eth_dev *dev)
  *   0 on success, errno value on failure.
  */
 static int
-priv_dev_set_link(struct priv *priv, struct rte_eth_dev *dev, int up)
+priv_dev_set_link(struct priv *priv, int up)
 {
-	int err;
-
-	if (up) {
-		err = priv_set_flags(priv, ~IFF_UP, IFF_UP);
-		if (err)
-			return err;
-		dev->tx_pkt_burst = priv_select_tx_function(priv, dev);
-		dev->rx_pkt_burst = priv_select_rx_function(priv, dev);
-	} else {
-		err = priv_set_flags(priv, ~IFF_UP, ~IFF_UP);
-		if (err)
-			return err;
-		dev->rx_pkt_burst = removed_rx_burst;
-		dev->tx_pkt_burst = removed_tx_burst;
-	}
-	return 0;
+	return priv_set_flags(priv, ~IFF_UP, up ? IFF_UP : ~IFF_UP);
 }
 
 /**
@@ -1357,7 +1421,7 @@ mlx5_set_link_down(struct rte_eth_dev *dev)
 	int err;
 
 	priv_lock(priv);
-	err = priv_dev_set_link(priv, dev, 0);
+	err = priv_dev_set_link(priv, 0);
 	priv_unlock(priv);
 	return err;
 }
@@ -1378,7 +1442,7 @@ mlx5_set_link_up(struct rte_eth_dev *dev)
 	int err;
 
 	priv_lock(priv);
-	err = priv_dev_set_link(priv, dev, 1);
+	err = priv_dev_set_link(priv, 1);
 	priv_unlock(priv);
 	return err;
 }
diff --git a/drivers/net/mlx5/mlx5_trigger.c b/drivers/net/mlx5/mlx5_trigger.c
index 1a20967a2..6f5c799b5 100644
--- a/drivers/net/mlx5/mlx5_trigger.c
+++ b/drivers/net/mlx5/mlx5_trigger.c
@@ -151,38 +151,23 @@ mlx5_dev_start(struct rte_eth_dev *dev)
 		      (void *)dev, strerror(err));
 		goto error;
 	}
-	/* Update send callback. */
-	dev->tx_pkt_burst = priv_select_tx_function(priv, dev);
 	err = priv_rxq_start(priv);
 	if (err) {
 		ERROR("%p: RXQ allocation failed: %s",
 		      (void *)dev, strerror(err));
 		goto error;
 	}
-	/* Update receive callback. */
-	dev->rx_pkt_burst = priv_select_rx_function(priv, dev);
-	err = priv_dev_traffic_enable(priv, dev);
-	if (err) {
-		ERROR("%p: an error occurred while configuring control flows:"
-		      " %s",
-		      (void *)priv, strerror(err));
-		goto error;
-	}
-	err = priv_flow_start(priv, &priv->flows);
-	if (err) {
-		ERROR("%p: an error occurred while configuring flows:"
-		      " %s",
-		      (void *)priv, strerror(err));
-		goto error;
-	}
 	err = priv_rx_intr_vec_enable(priv);
 	if (err) {
 		ERROR("%p: RX interrupt vector creation failed",
 		      (void *)priv);
 		goto error;
 	}
-	priv_dev_interrupt_handler_install(priv, dev);
 	priv_xstats_init(priv);
+	/* Update link status and Tx/Rx callbacks for the first time. */
+	memset(&dev->data->dev_link, 0, sizeof(struct rte_eth_link));
+	priv_link_update(priv, 1);
+	priv_dev_interrupt_handler_install(priv, dev);
 	priv_unlock(priv);
 	return 0;
 error:
-- 
2.11.0