From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from SJ2PR03CU001.outbound.protection.outlook.com (mail-westusazon11012025.outbound.protection.outlook.com [52.101.43.25]) (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 C45C1346AFB; Sat, 5 Sep 2026 03:25:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.43.25 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788578754; cv=fail; b=SKwkuiLV+X1IiKsHwc6HU0kC60il544XeOOwOysUkaV8kLhmfUJCDR11FvE/lcVfOg7atoL6CdO5Sz3XLclk+VXI3PFGA2qv8L3sG/eDb57lvLwbUEjH91EFYVSCHyaK7q3BsbQDIrmNKy4OtuyMDP47SVC7KFtyTN5Zh4vKvD4= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788578754; c=relaxed/simple; bh=3r6gMKvBW2LkPo/VnmQjCPYZPZ+k0rcMUKWzKA2QZTQ=; h=Date:From:To:CC:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=dMDFwseyvV6etCPQG1+hbR/8sBXqcFVPzmUJJndID/z6a0dYpA4gCAnDSuuOzjHf9z6XXUocr+VmGpPx+AaVhuk8AzArEdHbDbQkyHFH3i6Pn0Wi+2yQNoNNFCcwHlq67WddBwp9rkaqqQ4FzXrjiDIiVznNHAku2xRfy0hcCCs= 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=JuuEgRDn; arc=fail smtp.client-ip=52.101.43.25 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="JuuEgRDn" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=yAcCFaiVizlCmfvK/mknCZD5WV2kZbGg9Bgq7/rreuwzOeZAWVPMnV8DEkOnCV6z8FjQ6O1j5cbNXmh+mAUySyNQRLhzJGxXnQ6lqHEsjAIooqZ03A1nS1zZFbiw1k55R1zF6Ut6tAJf8MaLl8wyra8YkvDY8JjjgasN/8BlHUi+4Dmza88qd+6OKIpdG75Kqu/UY1kY4EVIlG9+Kk2gLGxA2Wo7Gsnklgy8aLxCQlIHaf+2ZB81A6v6vViPBrQkFellTqetnLSXqQ32rwFF98eFrtI4hXn6Xl/k7qD5NyrLYTW3uAzi5nXtsYTq4JRZboXa1tdRoeW9i7+WiEWU+g== 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=C87ceICwqHWFazhK3YCduUkTtmc6pkDDD2ghB3jqD3c=; b=xc1XwbMf3mjLMX9zva8wS4y/w1jMZb+zTDBeeAypNjaKqiT82/95/Vv8ssN829giKaW7hiXNuJwBzBPzC+a3iSFlgCWZ2yK8GxA4M52mwsh8U4IxEgzm5kVbNGSCc/EKBpJn/05uh6X3kwSh8gFUADdydJ45XvKcJcDQsszrRr3OKLkFUiCVK6RwUj0QMOL5JYk5NTCBlnxBVK6eKMEotfmXUj8rbj51qmWxS+zKsw0c4s+smhVHRN0nsGVd8S0L0xjkNFLCWkT9v0aOJ7Cro9qPpZ9/Fxn5cXgDtW2aA2OvG2ufWunquZvFebku0QV6x1S5jZktzFDgJhIuDjN3Kw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 216.228.117.160) smtp.rcpttodomain=oss.qualcomm.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=C87ceICwqHWFazhK3YCduUkTtmc6pkDDD2ghB3jqD3c=; b=JuuEgRDni6/KR+Gx39gY17p5VQonc1eHsqKYIhGPY5/jtiO9aRFFqzDQhTVcTYilWzE4ayjGjz8YTPwfdCrLbJnXdIwReJqx4jg4LAUx+kK3AILcuWLKMUqzayytDGxXaVler3/8Op3FkKhyA/FeohO0ES6X4m8dIkN64hMVEK6I9t99ipa5jpABl57BhjDalvM5Jw3o8IX+DtUoLf9BnjBDCnOmEKPUCIznTHWeOwp8zJ4PAjDLt7VTCPYCWRtr4Fyc9KtY1Y7j1H2lOBveM3YgGbzAbOcX2//cZM/l5rXuQnNI5fQhRUmXtKT1CEoFyJjMnqIhEfu/HdVQpBxR3w== Received: from BN9PR03CA0780.namprd03.prod.outlook.com (2603:10b6:408:13a::35) by PH7PR12MB6738.namprd12.prod.outlook.com (2603:10b6:510:1a9::16) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.360.12; Sat, 5 Sep 2026 03:25:41 +0000 Received: from BN7PEPF0000009E.namprd04.prod.outlook.com (2603:10b6:408:13a:cafe::3f) by BN9PR03CA0780.outlook.office365.com (2603:10b6:408:13a::35) with Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384) id 15.21.382.13 via Frontend Transport; Sat, 5 Sep 2026 03:25:41 +0000 X-MS-Exchange-Authentication-Results: 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 BN7PEPF0000009E.mail.protection.outlook.com (10.167.248.150) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.406.5 via Frontend Transport; Sat, 5 Sep 2026 03:25:39 +0000 Received: from rnnvmail202.nvidia.com (10.129.68.7) 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 15.2.2562.46; Fri, 4 Sep 2026 20:25:24 -0700 Received: from rnnvmail202.nvidia.com (10.129.68.7) by rnnvmail202.nvidia.com (10.129.68.7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.46; Fri, 4 Sep 2026 20:25:24 -0700 Received: from nvidia.com (10.127.8.13) by mail.nvidia.com (10.129.68.7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.46 via Frontend Transport; Fri, 4 Sep 2026 20:25:04 -0700 Date: Fri, 4 Sep 2026 20:24:54 -0700 From: Nicolin Chen To: Jonathan Cameron CC: , , , , , , , , , , , , , , , , , , Subject: Re: [PATCH v3 07/13] iommu/arm-smmu-v3: Disable the queue IRQs before disabling the SMMU Message-ID: References: <178846311318.1308030.6301643510859406126.b4-review@b4> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <178846311318.1308030.6301643510859406126.b4-review@b4> X-NV-OnPremToCloud: ExternallySecured X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BN7PEPF0000009E:EE_|PH7PR12MB6738:EE_ X-MS-Office365-Filtering-Correlation-Id: 81a19117-4dd0-4314-a0d6-08df0afd5bd6 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|7416014|23010399003|82310400026|1800799024|36860700016|10067099003|3023799007|22082099003|18002099003|11063799006|4143699003|5023799004|56012099006; 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)(376014)(7416014)(23010399003)(82310400026)(1800799024)(36860700016)(10067099003)(3023799007)(22082099003)(18002099003)(11063799006)(4143699003)(5023799004)(56012099006);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: ZdgvWQOQW7PyQD9IgXbDcjFR3oOZBbpje6jVmKo1wXLiAvFkh7LuRASbZgcKmgZPT9SQq+/fnCGN7LsJkF9YTtYhFnj3ujJ5HLff38MY3izJ0wiq0skjWARzv3ERvTMyRLjqa0Y+fze21IeQiIlcy3fpTA7FOcfGLjGfZpQC/U/ppEq37505dMeStmnZu0kwb8YKbTzCzeu6uZJxIB9pOq9H3UsBx4phF7I6bNZTpooP+uGx9WpVwe0gJDrFQQaBnrvBeZC6AszoER8qP/j8AySdpEHvZV9wnekTlFUWeg+wD4LygnqjaCtYdyOPIBKGwSvQjma9i4Hc5ix1pPstYbtuaq/Lgaveu4KLMDNpYZ8f3x6iHAC3w7PtyKm0eaNkj14T85AJUYLVeImQne2OTYKd5dS/NS+FklyN0B1HIbIPGe7L5A7I+IQlhSmYkmKp X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 05 Sep 2026 03:25:39.1774 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 81a19117-4dd0-4314-a0d6-08df0afd5bd6 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: BN7PEPF0000009E.namprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH7PR12MB6738 On Thu, Sep 03, 2026 at 12:18:33PM -0700, Jonathan Cameron wrote: > > The EVTQ, PRIQ and combined IRQ handlers are threaded and issue commands of > > their own, e.g. a CMDQ_OP_PRI_RESP for a page request. Disabling the SMMU > > while one is in flight hands that command to a queue consuming nothing, so > > its poll waits out a full timeout. > > > > Two paths disable the SMMU while those IRQs are still requested: a failing > > arm_smmu_device_reset() returns to a probe that disables the device itself, > > and arm_smmu_disable_action() covers an unbind or any later probe failure. > > Both can run after arm_smmu_setup_irqs() requested the IRQs. > > > > Disable those IRQs first in both paths, so that no handler is left running > > once the SMMU goes down. > > Why this soluton rather than a flag to stop them queuing new work + a > synchronize_irq() to deal with threads in flight. > > irq disables always worry me a little as they tend to be patching over > something nastier. I think this works though so I'm not going to > strongly object. Well, I don't see a reason to add extra flags: each irq here only has one single source, so disable_irq() is fundamentally similar to a flag + synchronize_irq(), but also masks the irq line, which makes sense in the probe-revert and shutdown paths. Above all, it is cleaner. If there is a solid reason for not using disable_irq() here, I'd not mind changing that though. Thanks Nicolin