Re: [PATCH rdma-next 1/2] RDMA/mlx5: Get upper device only if device is lagged

[Jason Gunthorpe <jgg@nvidia.com>]

On Wed, Aug 16, 2023 at 09:52:23AM +0300, Leon Romanovsky wrote:
> From: Mark Bloch <mbloch@nvidia.com>
> 
> If the RDMA device isn't in LAG mode there is no need
> to try to get the upper device.
> 
> Signed-off-by: Mark Bloch <mbloch@nvidia.com>
> Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
> ---
>  drivers/infiniband/hw/mlx5/main.c | 22 +++++++++++++++-------
>  1 file changed, 15 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
> index f0b394ed7452..215d7b0add8f 100644
> --- a/drivers/infiniband/hw/mlx5/main.c
> +++ b/drivers/infiniband/hw/mlx5/main.c
> @@ -195,12 +195,18 @@ static int mlx5_netdev_event(struct notifier_block *this,
>  	case NETDEV_CHANGE:
>  	case NETDEV_UP:
>  	case NETDEV_DOWN: {
> -		struct net_device *lag_ndev = mlx5_lag_get_roce_netdev(mdev);
>  		struct net_device *upper = NULL;
>  
> -		if (lag_ndev) {
> -			upper = netdev_master_upper_dev_get(lag_ndev);
> -			dev_put(lag_ndev);
> +		if (ibdev->lag_active) {

Needs locking to read lag_active

Jason