From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=pass header.oldest-pass=0 smtp.remote-ip=52.101.46.46 ARC-Seal: i=2; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=pass; t=1793123104; b=qTHI3Pfhl4ArWO8SdjtH4fEMdJ3Js652G4ILI05MGJDm6bbwJDhcGmtPVQM/MiWjyPzb 8QT6ubFjaf36fQ2TOF6iW5OSZBQzc/PWIEVa+Mg5fA7HgtHRG9YlMSkWdf9vZYBeMzFAm ZJU4GTcyLWBeZIeLN/4BrDV68mNPwHxtVdUmdyqgYJnuN99PaU64iBXuRFtmoCKGjObh9 ZDXyWpfd6P4MmknurMJfCRDODpLXYMmwMiP2ywKE6ozOY1FcgeDu2jikDi5EectltoBGl a35B3sBbLNeITPfcQFrZCnkpMldYwjt2X6A+yk3mP/zcJ/B/UNx0wpzlCwIcUf9GIsA== ARC-Message-Signature: i=2; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793123104; h=DMARC-Filter:DKIM-Signature:Received:Received: X-MS-Exchange-Authentication-Results:Received-SPF:Received:Received: Received:From:To:CC:Subject:Date:Message-ID:X-Mailer:In-Reply-To: References:MIME-Version:Content-Transfer-Encoding:Content-Type: X-Originating-IP:X-ClientProxiedBy:X-EOPAttributedMessage: X-MS-PublicTrafficType:X-MS-TrafficTypeDiagnostic: X-MS-Office365-Filtering-Correlation-Id:X-MS-Exchange-SenderADCheck: X-MS-Exchange-AntiSpam-Relay:X-Microsoft-Antispam: X-Microsoft-Antispam-Message-Info:X-Forefront-Antispam-Report: X-MS-Exchange-AntiSpam-MessageData-ChunkCount: X-MS-Exchange-AntiSpam-MessageData-0:X-OriginatorOrg: X-MS-Exchange-CrossTenant-OriginalArrivalTime: X-MS-Exchange-CrossTenant-Network-Message-Id: X-MS-Exchange-CrossTenant-Id: X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: X-MS-Exchange-CrossTenant-AuthSource:X-MS-Exchange-CrossTenant-AuthAs: X-MS-Exchange-CrossTenant-FromEntityHeader: X-MS-Exchange-Transport-CrossTenantHeadersStamped; bh=KO3KkTeUAAht2rR2iA4NLaD6mRMCJBFA9vBsn22Q/vM=; b=ssJQqhaQsCRFA8kr/fkt7duwhIX2FgFQZnGAAz8tY/ujSvf39M7ZVR4Vle2ysduvRNsZ csyc9T3zPDsF/G1pNaCtHmyLLt5BaL4j/gtNdeheD1kHcUu+vtauMUsw1nzjSfGGsLWhx j/r/8PLDP/MREfVcoQ0JqSn8oK7hxASFyQiRDNzL0EWR1TA749v14n7NLyywdvpZXofmS yEF4u72GdEJsv5M5mgPz9ND4tOuyvY+gWt7qPc2WSS4MRb5bRtgfVP36qW+KJpmQcYVhX PoMLL0zzXr54pI7UnUaOwPkpBLSHgJy1gopDku7i+F1qXMN20zrEIyVLqAnBN7tR4Fw== ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass header.d=Nvidia.com header.i=@Nvidia.com header.a=rsa-sha256 header.s=selector2 header.b=REValbVQ; arc=pass header.oldest-pass=0 smtp.remote-ip=52.101.46.46 Received: from CO1PR03CU002.outbound.protection.outlook.com (mail-westus2azon11010046.outbound.protection.outlook.com [52.101.46.46]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (secp384r1) server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D172F606A322; Tue, 27 Oct 2026 17:45:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org D172F606A322 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=nvidia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=Nvidia.com header.i=@Nvidia.com header.a=rsa-sha256 header.s=selector2 header.b=REValbVQ ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=di3L5oKR+EpvvOOHIf3Q5tltEEFR8DCCIwDHj1JHwWl7GaKy0attVGuyQswtm5VIEoTqTiw+BV8zUbG5gx9VrGRoTcSTZ3Z2QBKeTXbON4sYAjTfDrAHkzqfwfE8q8rUTtbruxz6I+4qu4gRuBIOovvwngEC6vetrZWu50eqD/FTX4BFNRGZlAiekL9eCf2BXyMsfEhJNhuYpi+bAdW0TRVhwE1yt3M0FzsfJS/OxX9KR1ouNcHCOc0FMeLoMjHyWVKNETYLhdDmb2SFwpSZ6XXSKgra+MB1pAckkgGELC3SffoHN3UDdCQK2wqQL8fLpk/TNDedPwxh+7uo21cJOQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=KO3KkTeUAAht2rR2iA4NLaD6mRMCJBFA9vBsn22Q/vM=; b=VR5ifXqrpu1iw7qhszN1QJ8lNGa4IyWUM5xs0nW/jiHREEgx0xB5jC4hN2cmWbUzRDOZjGhp8kf24HWyxKzmPGtuntLF7BdiZZ07MThYMDIuNdhr9DTOTwr7n0Fc9RO1oTa4aJiBmz9Sz8DYJ8ff08xCHUXmMNPvFJ01PQBg+Nrdr6poaEB+NJ3EkoYG8JKH4Y88MfE63fYg9kzDKK7me0vsDQ5EiTR+6ybmrs7o2F8cLT/ags0ERSQyqyWjdxXfm9+AQjwiOlvz6FZ9tmxVknsaFjCdyLyprQ03BmTwy1W38ezwCWT8p2IJxDUl8eUFWq7dFC9ypOIA302nKo/fAw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 216.228.117.160) smtp.rcpttodomain=microchip.com smtp.mailfrom=nvidia.com; dmarc=pass (p=reject sp=reject pct=100) action=none header.from=nvidia.com; dkim=none (message not signed); arc=none (0) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=KO3KkTeUAAht2rR2iA4NLaD6mRMCJBFA9vBsn22Q/vM=; b=REValbVQfbtpFRzB9ZX9FUPeY6noHHexM37516wEB/wCaWq25ERJ74ZWPOPlchTsQqmdaj750LNyikah9o/W67PmN3j1QbwwFZxfQVAYIyuBtcVK66W0IgYTrCrreqmMKDznwqWYS6iAiYHuTw9Iho0U5Fxgy/O4tmYkTICplpNSSZ0cMpgporvVP9HsSeXY66crOV+tLmgVce6fvyRLe9di1EMbO9sOj6rDuKPMDLFfOiLX7y0H3c35eykKQ4t7PiZ1GiJttUyC6AgkacZbPqAMYC6qdT3rFVCb54pa9DWFVhRd767u5jOC6RN62qrjAIzBnioicheU1ykg89ppMw== Received: from CYZPR17CA0018.namprd17.prod.outlook.com (2603:10b6:930:8c::15) by DS2PR12MB9774.namprd12.prod.outlook.com (2603:10b6:8:270::9) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.546.22; Tue, 27 Oct 2026 17:44:49 +0000 Received: from CY5PEPF00000E77.namprd02.prod.outlook.com (2603:10b6:930:8c:cafe::a1) by CYZPR17CA0018.outlook.office365.com (2603:10b6:930:8c::15) with Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384) id 15.21.546.22 via Frontend Transport; Tue, 27 Oct 2026 17:44:49 +0000 X-MS-Exchange-Authentication-Results: mx.microsoft.com 1; spf=pass (sender IP is 216.228.117.160) smtp.mailfrom=nvidia.com; dkim=none (message not signed) header.d=none;dmarc=pass action=none header.from=nvidia.com; Received-SPF: Pass (protection.outlook.com: domain of nvidia.com designates 216.228.117.160 as permitted sender) receiver=protection.outlook.com; client-ip=216.228.117.160; helo=mail.nvidia.com; pr=C Received: from mail.nvidia.com (216.228.117.160) by CY5PEPF00000E77.mail.protection.outlook.com (10.167.247.39) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.569.4 via Frontend Transport; Tue, 27 Oct 2026 17:44:49 +0000 Received: from rnnvmail201.nvidia.com (10.129.68.8) by mail.nvidia.com (10.129.200.66) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.56; Tue, 27 Oct 2026 10:44:26 -0700 Received: from vdi.nvidia.com (10.126.230.37) by rnnvmail201.nvidia.com (10.129.68.8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.56; Tue, 27 Oct 2026 10:44:24 -0700 From: Chris Babroski To: CC: , , , , , , , , , , , , , , Subject: Re: [PATCH net-next v1 3/5] net: lan743x: quiesce TX before freeing the rings Date: Tue, 27 Oct 2026 13:44:14 -0400 Message-ID: <20261027174414.578524-1-cbabroski@nvidia.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: References: X-Mailing-List: netdev@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain X-ClientProxiedBy: rnnvmail202.nvidia.com (10.129.68.7) To rnnvmail201.nvidia.com (10.129.68.8) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CY5PEPF00000E77:EE_|DS2PR12MB9774:EE_ X-MS-Office365-Filtering-Correlation-Id: 76f974c4-aca0-48ce-7dea-08df3451ff69 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|36860700016|23010399003|1800799024|376014|7416014|82310400026|261022075727099003|261022105027099003|261021123027099003|261009223027099003|10067099003|56012099006|261026121527099003|22082099003|18002099003|261026140227099003|11063799006; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:216.228.117.160;CTRY:US;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:mail.nvidia.com;PTR:dc6edge1.nvidia.com;CAT:NONE;SFS:(13230040)(36860700016)(23010399003)(1800799024)(376014)(7416014)(82310400026)(261022075727099003)(261022105027099003)(261021123027099003)(261009223027099003)(10067099003)(56012099006)(261026121527099003)(22082099003)(18002099003)(261026140227099003)(11063799006);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: iQAx/gdHa/xttNWhUNacgWjpYp+z31prZYcPh596ICUlrjJgoN/enF2nKQ6VP7ha8orMMVcnMJBrXr9pT8vmx/hhJHHxksdeQN/w0bKw3WfwZa8jTZ90ZOGOo+GW4CcUXxWWihRbetroc0WVUA++MaEmCL5ZBrZtn/6uUDwnD7BGYy4R47CxLGjx7RfO2bHfDKT/wLVkESogtl3LKlT13eGHn9xAFsaYuUv/qWlGmqS1xEnjPd975VHmmkK82WEUjH0GALpJ8Zw52wQqU5pl/3eauuviPR6Y1l8BMfG5cb8kgzcBkB+Uems5WkP6rIzjF3S9z7bJVntxyq5lTNEIlv6JRrqLiiipFenqGCZrzThjc/KSKfSWUuoo/uEKd4GBIG5P2uXGz4WFLpF6ag65ij3SHI1LRJmmnkkA67XyIHPvUzikW29wEmjMZudp0kcw X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 27 Oct 2026 17:44:49.0393 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 76f974c4-aca0-48ce-7dea-08df3451ff69 X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a;Ip=[216.228.117.160];Helo=[mail.nvidia.com] X-MS-Exchange-CrossTenant-AuthSource: CY5PEPF00000E77.namprd02.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS2PR12MB9774 Hi Woojung,=0D =0D > > @@ -3336,6 +3337,9 @@ static int lan743x_netdev_close(struct net_device= =0D > > *netdev)=0D > > =0D > > lan743x_phylink_disconnect(adapter);=0D > > =0D > > + synchronize_net();=0D > > + netif_tx_disable(netdev);=0D > =0D > synchronize_net() is called inside of lan743x_tx_close() and lan743x_rx_c= lose()=0D > via netif_napi_del(). Do you see current order of calling is an issue?=0D > =0D > > +=0D > > for (index =3D 0; index < adapter->used_tx_channels; index++)=0D > > lan743x_tx_close(&adapter->tx[index]);=0D =0D This was a change introduced after AI review flagged a potential race=0D condition:=0D 1. On CPU A, the TX NAPI poll now checks netif_device_present() and gets=0D true.=0D 2. On CPU B, netif_device_detach() runs, then lan743x_netdev_close()=0D calls netif_tx_disable() and the queue is stopped.=0D 3. CPU A calls netif_tx_wake_queue() and the queue is running again.=0D 4. The qdisc is still attached in the suspend and reset paths, so the=0D stack transmits into the ring while lan743x_tx_close() frees it.=0D =0D So the synchronize_net() called via lan743x_tx_close() can't prevent=0D NAPI poll from waking the queue again.=0D =0D The fix is to wait for NAPI poll to complete with synchronize_net()=0D first to prevent unexpected queue wake before netif_tx_disable() stops=0D the queue and waits for transmits to complete.=0D =0D This is unlikely to happen as part of the TX hang scenario because the=0D reset in that case comes after TX has stopped. The pre-existing=0D conditions that could see this would be suspend, reboot, or kexec on a=0D multi-core system under TX load.=0D =0D Given that this is not directly related to TX hang recovery I could=0D drop it from this patch series if you prefer.=0D =0D Thanks,=0D Chris=0D