Re: [PATCH 5.10 10/63] [PATCH] Revert "net/mlx5: Register to devlink ingress VLAN filter trap"

[Tariq Toukan <ttoukan.linux@gmail.com>]

On 9/24/2021 3:44 PM, Greg Kroah-Hartman wrote:
> From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> 
> This reverts commit fe6322774ca28669868a7e231e173e09f7422118 which was
> commit 82e6c96f04e13c72d91777455836ffd012853caa upstream.
> 
> It has been reported to cause regressions so should be dropped.
> 
> Reported-by: <Patrick.Mclean@sony.com>
> Link: https://lore.kernel.org/r/BY5PR13MB3604D3031E984CA34A57B7C9EEA09@BY5PR13MB3604.namprd13.prod.outlook.com
> Cc: Aya Levin <ayal@nvidia.com>
> Cc: Tariq Toukan <tariqt@nvidia.com>
> Cc: Tariq Toukan <tariqt@nvidia.com>
> Cc: Saeed Mahameed <saeedm@nvidia.com>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: Sasha Levin <sashal@kernel.org>
> Cc: Leon Romanovsky <leonro@nvidia.com>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> ---

Hi Greg,

This issue is solved within the same upstream series, by upstream patch:
[1] 241dc159391f net/mlx5: Notify on trap action by blocking event

We didn't spot the issue back then, the two patches should've been 
submitted in a reversed order in the original series to avoid this 
temporary degradation.

This patch "net/mlx5: Register to devlink ingress VLAN filter trap" is 
not a bug fix, not really needed in 5.10 stable.
I believe you cherry-picked it into 5.10 to handle some code context 
problem?

In summary, if the revert works for you w/o further degradation then we 
are fine with it. The alternative is to import the whole original 
series, especially the patch mentioned above [1].

Thanks,
Tariq

>   drivers/net/ethernet/mellanox/mlx5/core/devlink.c |   51 ----------------------
>   1 file changed, 51 deletions(-)
> 
> --- a/drivers/net/ethernet/mellanox/mlx5/core/devlink.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/devlink.c
> @@ -376,48 +376,6 @@ static void mlx5_devlink_set_params_init
>   #endif
>   }
>   
> -#define MLX5_TRAP_DROP(_id, _group_id)					\
> -	DEVLINK_TRAP_GENERIC(DROP, DROP, _id,				\
> -			     DEVLINK_TRAP_GROUP_GENERIC_ID_##_group_id, \
> -			     DEVLINK_TRAP_METADATA_TYPE_F_IN_PORT)
> -
> -static const struct devlink_trap mlx5_traps_arr[] = {
> -	MLX5_TRAP_DROP(INGRESS_VLAN_FILTER, L2_DROPS),
> -};
> -
> -static const struct devlink_trap_group mlx5_trap_groups_arr[] = {
> -	DEVLINK_TRAP_GROUP_GENERIC(L2_DROPS, 0),
> -};
> -
> -static int mlx5_devlink_traps_register(struct devlink *devlink)
> -{
> -	struct mlx5_core_dev *core_dev = devlink_priv(devlink);
> -	int err;
> -
> -	err = devlink_trap_groups_register(devlink, mlx5_trap_groups_arr,
> -					   ARRAY_SIZE(mlx5_trap_groups_arr));
> -	if (err)
> -		return err;
> -
> -	err = devlink_traps_register(devlink, mlx5_traps_arr, ARRAY_SIZE(mlx5_traps_arr),
> -				     &core_dev->priv);
> -	if (err)
> -		goto err_trap_group;
> -	return 0;
> -
> -err_trap_group:
> -	devlink_trap_groups_unregister(devlink, mlx5_trap_groups_arr,
> -				       ARRAY_SIZE(mlx5_trap_groups_arr));
> -	return err;
> -}
> -
> -static void mlx5_devlink_traps_unregister(struct devlink *devlink)
> -{
> -	devlink_traps_unregister(devlink, mlx5_traps_arr, ARRAY_SIZE(mlx5_traps_arr));
> -	devlink_trap_groups_unregister(devlink, mlx5_trap_groups_arr,
> -				       ARRAY_SIZE(mlx5_trap_groups_arr));
> -}
> -
>   int mlx5_devlink_register(struct devlink *devlink, struct device *dev)
>   {
>   	int err;
> @@ -432,16 +390,8 @@ int mlx5_devlink_register(struct devlink
>   		goto params_reg_err;
>   	mlx5_devlink_set_params_init_values(devlink);
>   	devlink_params_publish(devlink);
> -
> -	err = mlx5_devlink_traps_register(devlink);
> -	if (err)
> -		goto traps_reg_err;
> -
>   	return 0;
>   
> -traps_reg_err:
> -	devlink_params_unregister(devlink, mlx5_devlink_params,
> -				  ARRAY_SIZE(mlx5_devlink_params));
>   params_reg_err:
>   	devlink_unregister(devlink);
>   	return err;
> @@ -449,7 +399,6 @@ params_reg_err:
>   
>   void mlx5_devlink_unregister(struct devlink *devlink)
>   {
> -	mlx5_devlink_traps_unregister(devlink);
>   	devlink_params_unpublish(devlink);
>   	devlink_params_unregister(devlink, mlx5_devlink_params,
>   				  ARRAY_SIZE(mlx5_devlink_params));
> 
>