net/mlx5: Lag, update tracker when state change event received

Currently, In NETDEV_CHANGELOWERSTATE/NETDEV_CHANGEUPPERSTATE events
handling, tracking is not fully completed if the LAG device is not ready
at the time the events occur. But, we must keep track of the upper and
lower states after receiving the events because RoCE needs this info in
mlx5_lag_get_roce_netdev() - in order to return the corresponding port
that its running on. Returning the wrong (not most recent) port will lead
to gids table being incorrect.

For example: If during the attachment of a slave to the bond, the other
non-attached port performs pci_reload, then the LAG device is not ready,
but that should not result in dismissing attached slave tracker update
automatically (which is performed in mlx5_handle_changelowerstate()), Since
these events might not come later, which can lead to both bond ports
having tx_enabled=0 - which is not a valid state of LAG bond.

Fixes: 9b412cc ("net/mlx5e: Add LAG warning if bond slave is not lag master")
Signed-off-by: Maher Sanalla <msanalla@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Jianbo Liu <jianbol@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c

@@ -615,6 +615,7 @@ static int mlx5_handle_changeupper_event(struct mlx5_lag *ldev,
 	bool is_bonded, is_in_lag, mode_supported;
 	int bond_status = 0;
 	int num_slaves = 0;
+	int changed = 0;
 	int idx;
 
 	if (!netif_is_lag_master(upper))
@@ -653,27 +654,27 @@ static int mlx5_handle_changeupper_event(struct mlx5_lag *ldev,
 	 */
 	is_in_lag = num_slaves == MLX5_MAX_PORTS && bond_status == 0x3;
 
-	if (!mlx5_lag_is_ready(ldev) && is_in_lag) {
-		NL_SET_ERR_MSG_MOD(info->info.extack,
-				   "Can't activate LAG offload, PF is configured with more than 64 VFs");
-		return 0;
-	}
-
 	/* Lag mode must be activebackup or hash. */
 	mode_supported = tracker->tx_type == NETDEV_LAG_TX_TYPE_ACTIVEBACKUP ||
 			 tracker->tx_type == NETDEV_LAG_TX_TYPE_HASH;
 
-	if (is_in_lag && !mode_supported)
-		NL_SET_ERR_MSG_MOD(info->info.extack,
-				   "Can't activate LAG offload, TX type isn't supported");
-
 	is_bonded = is_in_lag && mode_supported;
 	if (tracker->is_bonded != is_bonded) {
 		tracker->is_bonded = is_bonded;
-		return 1;
+		changed = 1;
 	}
 
-	return 0;
+	if (!is_in_lag)
+		return changed;
+
+	if (!mlx5_lag_is_ready(ldev))
+		NL_SET_ERR_MSG_MOD(info->info.extack,
+				   "Can't activate LAG offload, PF is configured with more than 64 VFs");
+	else if (!mode_supported)
+		NL_SET_ERR_MSG_MOD(info->info.extack,
+				   "Can't activate LAG offload, TX type isn't supported");
+
+	return changed;
 }
 
 static int mlx5_handle_changelowerstate_event(struct mlx5_lag *ldev,
@@ -716,9 +717,6 @@ static int mlx5_lag_netdev_event(struct notifier_block *this,
 
 	ldev    = container_of(this, struct mlx5_lag, nb);
 
-	if (!mlx5_lag_is_ready(ldev) && event == NETDEV_CHANGELOWERSTATE)
-		return NOTIFY_DONE;
-
 	tracker = ldev->tracker;
 
 	switch (event) {