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Miller" , Eric Dumazet , Paolo Abeni , Maxime Coquelin , Alexandre Torgue , Jose Abreu , Rohan G Thomas , netdev@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Matthew Gerlach , "Ng, Boon Khai" References: <20250915-qbv-fixes-v2-0-ec90673bb7d4@altera.com> <20250915-qbv-fixes-v2-2-ec90673bb7d4@altera.com> <20250917154920.7925a20d@kernel.org> <20250917155412.7b2af4f1@kernel.org> Content-Language: en-US From: "G Thomas, Rohan" In-Reply-To: <20250917155412.7b2af4f1@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: MA5PR01CA0005.INDPRD01.PROD.OUTLOOK.COM (2603:1096:a01:174::9) To DM6PR03MB5371.namprd03.prod.outlook.com (2603:10b6:5:24c::21) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DM6PR03MB5371:EE_|SJ0PR03MB5616:EE_ X-MS-Office365-Filtering-Correlation-Id: f542630e-b502-4bb5-924b-08ddfb268094 X-MS-Exchange-AtpMessageProperties: SA X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|7416014|366016|376014|1800799024; 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>>> + if (has_vlan) { >>> + /* Add VLAN tag length to sdu length in case of txvlan offload */ >>> + if (priv->dev->features & NETIF_F_HW_VLAN_CTAG_TX) >>> + sdu_len += VLAN_HLEN; >>> + if (skb->vlan_proto == htons(ETH_P_8021AD) && >>> + priv->dev->features & NETIF_F_HW_VLAN_STAG_TX) >>> + sdu_len += VLAN_HLEN; >> >> Is the device adding the same VLAN tag twice if the proto is 8021AD? >> It looks like it from the code, but how every strange.. >> >> In any case, it doesn't look like the driver is doing anything with >> the NETIF_F_HW_VLAN_* flags right? stmmac_vlan_insert() works purely >> off of vlan proto. So I think we should do the same thing here? > > I suppose the double tagging depends on the exact SKU but first check > looks unnecessary. Maybe stmmac_vlan_insert() should return the number > of vlans it decided to insert? > I overlooked the behavior of stmmac_vlan_insert(). It seems the hardware supports inserting only one VLAN tag at a time, with the default setting being SVLAN for 802.1AD and CVLAN for 802.1Q. I'll update the patch to simply add VLAN_HLEN when stmmac_vlan_insert() returns true. Please let me know if you have any further concerns. Best Regards, Rohan