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dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from CHAPR12MB999248.namprd12.prod.outlook.com (2603:10b6:610:2ff::22) by IA6PR12MB074433.namprd12.prod.outlook.com (2603:10b6:208:5fc::19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.546.19; Fri, 23 Oct 2026 13:15:04 +0000 Received: from CHAPR12MB999248.namprd12.prod.outlook.com ([fe80::4972:8062:d74e:b205]) by CHAPR12MB999248.namprd12.prod.outlook.com ([fe80::4972:8062:d74e:b205%6]) with mapi id 15.21.0546.012; Fri, 23 Oct 2026 13:15:04 +0000 Message-ID: Date: Fri, 23 Oct 2026 15:14:59 +0200 User-Agent: Mozilla Thunderbird Subject: Re: mlx5e:zero-prefix corruption during TCP DMA-BUF RX - help requested To: jiabin deng Cc: netdev@vger.kernel.org, saeedm@nvidia.com, tariqt@nvidia.com, mbloch@nvidia.com, linux-kernel@vger.kernel.org References: Content-Language: en-US From: Dragos Tatulea In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-ClientProxiedBy: FR4P281CA0287.DEUP281.PROD.OUTLOOK.COM (2603:10a6:d10:e7::12) To CHAPR12MB999248.namprd12.prod.outlook.com (2603:10b6:610:2ff::22) X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CHAPR12MB999248:EE_|IA6PR12MB074433:EE_ X-MS-Office365-Filtering-Correlation-Id: 521edfea-f057-440d-34ce-08df3107a69e X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|23010399003|366016|1800799024|376014|22082099003|18002099003|10067099003|11063799006|56012099006|4143699003|261022113327099003|261022105027099003|261022075727099003|261021121427099003; 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With > MTU set to 1500, the single-direction test covered eight message > sizes, with 50 transfers per size, for a total of 400 transfers. > > All 400 transfers completed successfully. Full payload comparisons > found zero failing cases, zero incorrect bytes, and zero corrupted > intervals. The zero-prefix corruption observed in the earlier tests > did not recur in this patched run. > > Thank you for continuing to investigate this issue and for suggesting > the fix. I also greatly appreciate the time and effort you and the > other maintainers dedicate to the open-source community. As a student, > I am excited to have the opportunity to contribute to the community > and to learn from this process. > Thank you for your good analysis and fast response! > I would be happy to help prepare a formal patch with the test results. > Would you prefer to submit the fix yourself, or would it be helpful > for me to prepare and submit it based on your suggested change? > I am still waiting for input from the HW folks to understand if this change is needed for all SHAMPO cases or only specific P2P DMA cases. I think you should submit the fix as you did most of the work. Just give me some time to check the above. I'll ping you hopefully next week. Thanks, Dragos