Message-ID: <a8677175-0d4f-af01-23d4-ad014697bee7@intel.com>
Date:   Tue, 7 Feb 2023 11:03:24 -0800
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Subject: Re: [PATCH net 2/3] i40e: add double of VLAN header when computing
 the max MTU
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To:     Jason Xing <kerneljasonxing@gmail.com>,
        <jesse.brandeburg@intel.com>, <davem@davemloft.net>,
        <edumazet@google.com>, <kuba@kernel.org>, <pabeni@redhat.com>,
        <richardcochran@gmail.com>, <ast@kernel.org>,
        <daniel@iogearbox.net>, <hawk@kernel.org>,
        <john.fastabend@gmail.com>, <alexandr.lobakin@intel.com>,
        <maciej.fijalkowski@intel.com>
CC:     <intel-wired-lan@lists.osuosl.org>, <netdev@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <bpf@vger.kernel.org>,
        Jason Xing <kernelxing@tencent.com>
References: <20230204133535.99921-1-kerneljasonxing@gmail.com>
 <20230204133535.99921-3-kerneljasonxing@gmail.com>
From:   Tony Nguyen <anthony.l.nguyen@intel.com>
In-Reply-To: <20230204133535.99921-3-kerneljasonxing@gmail.com>
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On 2/4/2023 5:35 AM, Jason Xing wrote:
> From: Jason Xing <kernelxing@tencent.com>
> 
> 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@tencent.com>
> ---
>   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