From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from CH1PR05CU001.outbound.protection.outlook.com (mail-northcentralusazon11010044.outbound.protection.outlook.com [52.101.193.44]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5F04343DA27; Tue, 31 Mar 2026 19:58:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.193.44 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774987137; cv=fail; b=Urfit317OOHgpaAaUb3KXUl4DAnyVPc+E7jJPgCYQMSaeer3pbXP0S30SKbFtxz6CTn8Mo2rtD9jjHKZc940eLbaEmlhoYPmG2H0WHStHIzSpxfPjTU3w2vyslEtgp4XwOX7mw22DoADE1F76UvtMA5yLJWRtOr/DHcos0sipbs= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774987137; c=relaxed/simple; bh=qdj3MbNVayYQcQ0BLeqx1Qs8mi25fh79LGUqSD6RiaQ=; h=Date:From:To:Cc:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:MIME-Version; b=OYP2QCkjeI+xKmazlggOE0SXbSvd0FQObhkN+O0eK6WrEsM5FOf2z5f4NHcbr4zqw08KtsJ/n/RXDmh8PHjq1Y80WnrX3lW/o6Z+qWz7e0rFl3lYeW2NvfTm5LRagzjAjMMyzUUQCdAUQu+QpZHf0Y50vf12eM7DMXMp2X5pMbE= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b=upFKk1EP; arc=fail smtp.client-ip=52.101.193.44 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) header.d=Nvidia.com header.i=@Nvidia.com header.b="upFKk1EP" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=WtwAMMKcKiG4n14hPP3McN6QpWRFb/6sKb66DO9+y+nzE3mQVShnv/In5RGGKxJxGpTqtnGTiOUEVxLeIVYd8QT5XZenVc887WdK3uaSDvK3hWe/T3x5913rsRpY1ngrGUyaI6Zdnsgk4odDY2WBlLKakUnaC2aWUiT7ayXMExtl5r04LmbgaufNJYXs4AfzjDJrJZFOebgba8W7OvCilRCECpsXSAU6rw2Hd6uvbIUSn00AD7TA/PPKQ+ISZ16vSs0qopQD7NF1T2qrGnXYPunhOWQ+d6ouIvX1CmbvejDSsSV1V0x6XN+lV5pPiHn4OSpDttgLxHyiYZ7wCNKCFg== 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=Ncm9WJJ42JFGt3EUPh3kQgJE17tTiF9YzPoIoBzrEH0=; b=FOR342WEaw1XVZS9OSrSdEsJWQxGWuk9CiMKpJmzLOtPeU+gVmzzqUTGsGqDWFuMuDZYdU43IYmNARDbBCrIyacZy1U2gmHLdvcLuchFkkZDgIlczrVdP2Txm+X0p4d8AAsByAb0tkEJYVPp68JOeBkERTibfcEaJZFxttWEOSMctYa/0J4Rdhv5pYhMaYo5MLZoRK/jpqyF3x/rpi2Q5iTF+ZyAmPooRpi8h4OW7PpgtU+Za2TYkG1ef7RSW198WPRHejG80+f3fJeNw6QuEZZztq6B4emp2PB1CGAKSZO626EyOaCisJXdZwrm0XtMWUmq6/CMt/GlpitdWStgjQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none 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=Ncm9WJJ42JFGt3EUPh3kQgJE17tTiF9YzPoIoBzrEH0=; b=upFKk1EPP9AjoUtyX60+gO1KL8ctbdPgvZAAiyTCbFoFRKq1iER6e8brbcusn6mKWvFhnQHaxxr3H7EtlapCQ4j8rzgBVXOGyLZ66Rl8uQyQBVRM6dwn7Gpjqf/uBxt/TXh0/GBlJn4Rlxk0JCxngpQzG71yvOM/oEBl4WM4MkCGRpmIHVuAb2AdwSq9EM3mCrQEqYEjtftfnTWSH5YoB2o7M/QRfnVaiYmNMJzCcu0S7Amyh67nGLog3CmlrFvTyzpXmtlt0fToypGPPoEtnqi0Ulj0XKS4jAOjtI9p9AOrihIoq3kII+vveOIG4HKAykgD8zy52qOlsM0SULRN4g== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from LV8PR12MB9620.namprd12.prod.outlook.com (2603:10b6:408:2a1::19) by CY5PR12MB9053.namprd12.prod.outlook.com (2603:10b6:930:37::13) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9769.16; Tue, 31 Mar 2026 19:58:46 +0000 Received: from LV8PR12MB9620.namprd12.prod.outlook.com ([fe80::299d:f5e0:3550:1528]) by LV8PR12MB9620.namprd12.prod.outlook.com ([fe80::299d:f5e0:3550:1528%5]) with mapi id 15.20.9769.014; Tue, 31 Mar 2026 19:58:46 +0000 Date: Tue, 31 Mar 2026 16:58:44 -0300 From: Jason Gunthorpe To: Jon Hunter Cc: iommu@lists.linux.dev, Joerg Roedel , Robin Murphy , Will Deacon , Alejandro Jimenez , Janusz Krzysztofik , Joerg Roedel , Kevin Tian , Pasha Tatashin , patches@lists.linux.dev, Samiullah Khawaja , stable@vger.kernel.org, "linux-tegra@vger.kernel.org" Subject: Re: [PATCH rc 1/2] iommu: Do not call drivers for empty gathers Message-ID: <20260331195844.GY310919@nvidia.com> References: <1-v1-13a02eb0e031+a5-iommu_gather_jgg@nvidia.com> <8800a38b-8515-4bbe-af15-0dae81274bf7@nvidia.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8800a38b-8515-4bbe-af15-0dae81274bf7@nvidia.com> X-ClientProxiedBy: MN0PR05CA0027.namprd05.prod.outlook.com (2603:10b6:208:52c::24) To LV8PR12MB9620.namprd12.prod.outlook.com (2603:10b6:408:2a1::19) Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: LV8PR12MB9620:EE_|CY5PR12MB9053:EE_ X-MS-Office365-Filtering-Correlation-Id: 4fe74466-3903-4b12-fd88-08de8f5feb0c X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|7416014|1800799024|366016|56012099003|18002099003|22082099003; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:LV8PR12MB9620.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(7416014)(1800799024)(366016)(56012099003)(18002099003)(22082099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?dWtnGGp/elCDsCXI6iZ6TndcByYN7GNMeZT3XvfQIGhSIdWcUWHu/lQx3o5/?= =?us-ascii?Q?jEkFcsGFnNw3ZKLFfMmJFjRYNmYDgRnA3Bb7IcADGCTb6R986fMVh7RdDFcn?= =?us-ascii?Q?xqkEfPFWjQfj4pZQkku817FJaW4Skcsncxi4nl3VlsBJiZSMm2zlOnRNiDWi?= =?us-ascii?Q?cBTlt8oca7P25v5T4gWjbwev1Ve/Z4RMvyIQGAs9uqMyYk0DEP6Qh/BQ9oFC?= =?us-ascii?Q?2P0EZR0IkXofMj+2IG6rbEOTvwcFw8zbn8p3UKYlU/tXpcvhoreM3+ibpzYw?= =?us-ascii?Q?Ol8nlPVoAIpTl+GnkY4XfTUH4EWnqq1AoQ4M7IHS7QAnF63oRuBojTlsjrPg?= =?us-ascii?Q?G+llhh1r9gTv48HwMQqC18jCeSgxGDGog7Ocxx7oyIneCj7H/iwICIDW7zIh?= =?us-ascii?Q?VqxpKsOm9NqwGgELC2Ue2KVDDsPZeTt1U1ZDozi9yQyracLUAW7BcGmWwUdP?= =?us-ascii?Q?Hv+S5H2EXN9hLuG8idIDOurs+2ZXo6ReF13fgniFRRF2Uaa6eEqk1wG1mJxV?= =?us-ascii?Q?TfEUeJwnPflasUYqDdLHQCXR9Yuf2F3xHy7Qh6xYujj6hp9Nb3PuMnYz0PQ0?= =?us-ascii?Q?6N+uKnRTb7v2Gs3ggZFgcF0PloZdTiYg954o5GFlP7sOPBnHYblOTNr4UF3a?= =?us-ascii?Q?JBy9gAw9Q0FimYp+fSoW24dKCq4UMgJLUMGIIeWij+ZYnxR2cV9PtDDgEx0I?= =?us-ascii?Q?cDMoy8v/CNkrFhkhVpQyd4278e/LWD+dPniC4jmHWoUrFRXVmNy3jdBFGOJQ?= =?us-ascii?Q?ARFn/5JR4OgjsCLSHb29uRRRODaZZwX74xIV05/qVOIHqDqKdsjwiAY4C+xQ?= =?us-ascii?Q?QI1RWl+sKu0sTsxtANf80vOs596a8DE6LdUX0ngW3HjUnzNpd8WHOGDQXyjv?= =?us-ascii?Q?10MD/U3YapLQxmMc89CUJGSeFov5PkKFDwbQ+Be1S7CmSfU+YEKxoSWujyLg?= =?us-ascii?Q?o5ARoErcRH1xugsk9HvK0tGEGWK8Qy2x/shfkdPQLSTjJ6EwLGkwNGYj689T?= =?us-ascii?Q?5Tv57KHgSOPlPNHvIQg1r/SDMv86wckejHLilcJlmUSzE3u8KYJkt2mehYLS?= =?us-ascii?Q?IHunklLEZkCwOaCuGHon17kEfEYNY9uUa9F7BnH5TSW+wSqeV/KDUqBsmKD8?= =?us-ascii?Q?wZHOnQFBtvEGNi8OWW8zz+52LjvcqeNLKvuvCk2kYL6KKubSK+IwD7qvU8bJ?= =?us-ascii?Q?0OUqpLDKAtJk/OTgk6ObkWW/C/l3w4BATYyfTPQfwtVr8GJxeZ2T2GuoZoIb?= =?us-ascii?Q?i+3LRl9J9BAJgmQjikSFzWjDE3BsPB7rBxXn3Sesufoue7e6uQHwf+02j9vN?= =?us-ascii?Q?Y+zx1bkeocjHyEZoLwrde+Lry23N14zsyMaBlht0PAk03D4dB737TjyiIuVi?= =?us-ascii?Q?rajJYfjj7h8rlWkt5WETG1Zs1HrWrmU8XiHc7qZSpHMeVO1MyJlmLlZO89hB?= =?us-ascii?Q?TrGkI7qqm8gvlcpSm5laLME304qccf7F5nXo5MHl/E47KWMY4mhxhhFc/BXm?= =?us-ascii?Q?82TDGU44ryu2ToHIi9Lc/0ZKBDdNT0g3h5n1JP5Siv+dFn6HHTX70yB6E77J?= =?us-ascii?Q?+LZEQFqrVsABcH/w5zqwdyo695phNN4ToBMDq5baXF1zOnQ06m3XiIxmDwaO?= =?us-ascii?Q?HVeV05ET+XiHmcykbn8ayftGx+Y1XsKVu3EgxYVc+jXG04uqU2HWP9+zKXWM?= =?us-ascii?Q?0quza0yAAj8S4O+aQUa+LUh5Ptkr2FivRLFbDs1ZiP5XJNIX?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 4fe74466-3903-4b12-fd88-08de8f5feb0c X-MS-Exchange-CrossTenant-AuthSource: LV8PR12MB9620.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 31 Mar 2026 19:58:46.3317 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: SsyEBU0OPrxxcsXChRXM/t5m59octsFr5rN+m4uHyc7nahW5WoP/35X6aou1Iuf2 X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY5PR12MB9053 On Tue, Mar 31, 2026 at 06:12:18PM +0100, Jon Hunter wrote: > I noticed that a couple of our Tegra boards are no longer booting -next and > bisect pointed to this commit. Reverting this does fix it. > > This is impacting our Tegra186 (using nvidia,tegra186-smmu compatible > string) and Tegra194 (using nvidia,tegra194-smmu compatible string) boards. > There is no specific crash I see, but the boards just appear to hang on > boot. If you have any thoughts or things to try let me know. Thanks, I was able to guess what the problem is: https://patch.msgid.link/r/0-v1-664d3acaabb9+78b-iommu_gather_always_jgg@nvidia.com Please let me know if it doesn't solve the problem Jason