Re: [PATCH net 2/3] i40e: add double of VLAN header when computing the max MTU

[Tony Nguyen]

On 2/4/2023 5:35 AM, Jason Xing wrote:
> From: Jason Xing <kernelxing@xxxxxxxxxxx>
>
> Include the second VLAN HLEN into account when computing the maximum
> MTU size as other drivers do.
>
> Fixes: 0c8493d90b6b ("i40e: add XDP support for pass and drop actions")
> Signed-off-by: Jason Xing <kernelxing@xxxxxxxxxxx>
> ---
>   drivers/net/ethernet/intel/i40e/i40e.h      | 2 ++
>   drivers/net/ethernet/intel/i40e/i40e_main.c | 2 +-
>   2 files changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/intel/i40e/i40e.h b/drivers/net/ethernet/intel/i40e/i40e.h
> index 60e351665c70..e03853d3c706 100644
> --- a/drivers/net/ethernet/intel/i40e/i40e.h
> +++ b/drivers/net/ethernet/intel/i40e/i40e.h
> @@ -107,6 +107,8 @@
>   #define I40E_BW_MBPS_DIVISOR		125000 /* rate / (1000000 / 8) Mbps */
>   #define I40E_MAX_BW_INACTIVE_ACCUM	4 /* accumulate 4 credits max */
>   
> +#define I40E_PACKET_HDR_PAD (ETH_HLEN + ETH_FCS_LEN + (VLAN_HLEN * 2))

This already exists:
https://elixir.bootlin.com/linux/latest/source/drivers/net/ethernet/intel/i40e/i40e_txrx.h#L112