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Date:   Tue, 8 Nov 2022 07:18:24 +0100
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Subject: Re: [PATCH 01/14] net: ethernet: mtk_eth_soc: account for vlan in rx
 header length
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To:     Vladimir Oltean <olteanv@gmail.com>
Cc:     netdev@vger.kernel.org, John Crispin <john@phrozen.org>,
        Sean Wang <sean.wang@mediatek.com>,
        Mark Lee <Mark-MC.Lee@mediatek.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org
References: <20221107185452.90711-1-nbd@nbd.name>
 <20221107205553.cnydzeh3tmilqblx@skbuf>
From:   Felix Fietkau <nbd@nbd.name>
In-Reply-To: <20221107205553.cnydzeh3tmilqblx@skbuf>
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On 07.11.22 21:55, Vladimir Oltean wrote:
> On Mon, Nov 07, 2022 at 07:54:39PM +0100, Felix Fietkau wrote:
>> This may be needed for correct MTU settings on devices using DSA
>> 
>> Signed-off-by: Felix Fietkau <nbd@nbd.name>
>> ---
>>  drivers/net/ethernet/mediatek/mtk_eth_soc.h | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
>> index 589f27ddc401..dcf2a0d5da33 100644
>> --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
>> +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
>> @@ -29,7 +29,7 @@
>>  #define MTK_TX_DMA_BUF_LEN_V2	0xffff
>>  #define MTK_DMA_SIZE		512
>>  #define MTK_MAC_COUNT		2
>> -#define MTK_RX_ETH_HLEN		(ETH_HLEN + ETH_FCS_LEN)
>> +#define MTK_RX_ETH_HLEN		(VLAN_ETH_HLEN + ETH_HLEN + ETH_FCS_LEN)
> 
> Commit title says account for VLAN (VLAN_HLEN, 4 bytes), code says add
> VLAN_ETH_HLEN (18) more bytes.
> 
> Also, why is DSA mentioned in the commit message? Is accounting for VLAN
> hlen not needed if DSA is not used? Why?
Will fix the code and improve the comments in v2.

- Felix