From: Jakub Kicinski <kuba@kernel.org>
Date: Wed, 19 May 2021 10:18:25 -0700
Subject: mlx5: count all link events
Patch-mainline: v5.14-rc1
Git-commit: 490dcecabbf93e705006af498fa6815251404a54
References: git-fixes
mlx5 devices were observed generating MLX5_PORT_CHANGE_SUBTYPE_ACTIVE
events without an intervening MLX5_PORT_CHANGE_SUBTYPE_DOWN. This
breaks link flap detection based on Linux carrier state transition
count as netif_carrier_on() does nothing if carrier is already on.
Make sure we count such events.
netif_carrier_event() increments the counters and fires the linkwatch
events. The latter is not necessary for the use case but seems like
the right thing to do.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 6 +++++-
include/linux/netdevice.h | 2 +-
net/sched/sch_generic.c | 18 ++++++++++++++++++
3 files changed, 24 insertions(+), 2 deletions(-)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -133,12 +133,16 @@ void mlx5e_update_carrier(struct mlx5e_p
{
struct mlx5_core_dev *mdev = priv->mdev;
u8 port_state;
+ bool up;
port_state = mlx5_query_vport_state(mdev,
MLX5_VPORT_STATE_OP_MOD_VNIC_VPORT,
0);
- if (port_state == VPORT_STATE_UP) {
+ up = port_state == VPORT_STATE_UP;
+ if (up == netif_carrier_ok(priv->netdev))
+ netif_carrier_event(priv->netdev);
+ if (up) {
netdev_info(priv->netdev, "Link up\n");
netif_carrier_on(priv->netdev);
} else {
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -3813,8 +3813,8 @@ unsigned long dev_trans_start(struct net
void __netdev_watchdog_up(struct net_device *dev);
void netif_carrier_on(struct net_device *dev);
-
void netif_carrier_off(struct net_device *dev);
+void netif_carrier_event(struct net_device *dev);
/**
* netif_dormant_on - mark device as dormant.
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -514,6 +514,24 @@ void netif_carrier_off(struct net_device
}
EXPORT_SYMBOL(netif_carrier_off);
+/**
+ * netif_carrier_event - report carrier state event
+ * @dev: network device
+ *
+ * Device has detected a carrier event but the carrier state wasn't changed.
+ * Use in drivers when querying carrier state asynchronously, to avoid missing
+ * events (link flaps) if link recovers before it's queried.
+ */
+void netif_carrier_event(struct net_device *dev)
+{
+ if (dev->reg_state == NETREG_UNINITIALIZED)
+ return;
+ atomic_inc(&dev->carrier_up_count);
+ atomic_inc(&dev->carrier_down_count);
+ linkwatch_fire_event(dev);
+}
+EXPORT_SYMBOL_GPL(netif_carrier_event);
+
/* "NOOP" scheduler: the best scheduler, recommended for all interfaces
under all circumstances. It is difficult to invent anything faster or
cheaper.