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Wysocki" , Will Deacon , Lu Baolu , Kevin Tian , Chen-Yu Tsai Subject: Re: [PATCH v2 0/4] Fix device_lock deadlock on two probe() paths Message-ID: References: <0-v2-d2762acaf50a+16d-iommu_group_locking2_jgg@nvidia.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: BL1PR13CA0308.namprd13.prod.outlook.com (2603:10b6:208:2c1::13) To LV2PR12MB5869.namprd12.prod.outlook.com (2603:10b6:408:176::16) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: LV2PR12MB5869:EE_|PH7PR12MB8177:EE_ X-MS-Office365-Filtering-Correlation-Id: 40c450cf-80f2-48d1-adda-08dba02010c9 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; 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:LV2PR12MB5869.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230031)(376002)(39860400002)(346002)(366004)(136003)(396003)(451199024)(186009)(1800799009)(54906003)(66946007)(316002)(66556008)(66476007)(6916009)(41300700001)(5660300002)(38100700002)(4326008)(8676002)(8936002)(26005)(2906002)(4744005)(83380400001)(478600001)(86362001)(7416002)(6506007)(6512007)(36756003)(2616005)(6486002);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?dwXQQNnZjIspXigISDiwrMeq/VPPKVsSxLo0mQZHerP8Fx2hlAyWjfiQPjyj?= =?us-ascii?Q?u2OvDV51XKFqARFZMODWc4R+ffn4rcIcjCT2Thg44YSIgOeMuZsgRYPWrSDo?= =?us-ascii?Q?LvXWwgivzcwPLJ2ehmums6FNTOG2gWmC4mwbLYCyz5Re07zhNyUM1cgK3C7b?= =?us-ascii?Q?WO3vjrN5pyTC0elU/5zRNFsNpb7fCqFeZXY5f7EB+YZWQ7F86vznlB+gzYhM?= =?us-ascii?Q?oBJ40RuLgi2JYS721HGqeafgommF2GEVz0+9vj682P6OmM5l9ME+G1QESL0g?= =?us-ascii?Q?QMZv5QIB/ucwnkYgVInLkTLn1iQjoqQEcm1NimGE3l9CJDPxPvRX/o7048DK?= =?us-ascii?Q?no8nNP5kkb9Q5LlU0ckBV5KkRfQSqIykO0NJ0zHgkg9VDDk+Kuf8llYIHA9E?= =?us-ascii?Q?QgVMF4sS5egryMtUJeuwhi+e7LyxGXBpTc4Cznp7s523AmpFAWN0XSJS5WXP?= =?us-ascii?Q?3hHt2eHHvmem7D/V5WlJKR+Ip66w9cuhv2IewwNDg4BHWthTMjWOT7WNw78R?= =?us-ascii?Q?tY7XzeufgIyW/Ari2nH2SjMXGvpobaoX+S2uAlpl7jMieM0hBZlqDJmwhG8R?= =?us-ascii?Q?INKWzkWzBVAha5dqXXwd6YfWYbOLCwPJmjVmFqJt4uDmPIEN3RNADH9Fa5QQ?= =?us-ascii?Q?6tu3LHupHcjxiUCXIKtTJCuXi9MG4KjQ9bm//pEWh7qzNtuF8SJD2O0OUs2c?= =?us-ascii?Q?5UrqdkAkH4VwmAT7HQnd7XLRrgo7PFLoVaxU93mbUHM0uhQKHZvbrL4Svxv6?= =?us-ascii?Q?up2plx8O5V7vQqd0wtU4HIvX1EaypEeQJ/gLryfqtq2kQiRjwEdIaIG+6t2S?= =?us-ascii?Q?iM4EppJgBF4wtjjiMsG8zEnKC2o82ARBmc7n6vHoGulcS6vEfdo5VNw/ICgs?= =?us-ascii?Q?yIenIyW3Fi/D9FFwVEljKRYJP5pjaldgt56tG2WTXEsdvXEk4toCGkhbjkzN?= =?us-ascii?Q?GuGTNdQeCAbdieDpdo9AujJregB/M4UYFopSvEjblvqKcOB8KcHti37H6MQk?= =?us-ascii?Q?NJn5VYrTQE7I2iymIik0BKOhYfjlMPAb5pdAxlkjXfmI+2WHnlfm/HEnKVPB?= =?us-ascii?Q?uMUDNDLOsakYNRVoyoW+A/cPbTsyYaxeB0qEXJgIdxqH0VcWvupLSYxW+GRA?= =?us-ascii?Q?Zib8rNb6o9p2b+EiIi2Qq/3Yt7b/UrEXA/7GAsafycooCH49dWecUymi92zs?= =?us-ascii?Q?aa9lfBuNKnsEufmY5ZXkzXxTcPEZgYP0gbOIX8STpdWFY4McpyFiVb1L5DRn?= =?us-ascii?Q?qxoBwTXDkHm1+exOCqJ9ce64DoJC1kpgbeCgiJ80xDBFZWxBx67ouftGWX/x?= =?us-ascii?Q?fzMDGNNbUIN/hTfSlA8c/yP4ku9r/kjtgk3LmljNm6L1MVq9r7RA1grtgAW3?= =?us-ascii?Q?c2SP+BEcVqHE4XwknglN+nLxM45kUoFu5JlqxhJKl5CkZRAE9RQptFvVh9NO?= =?us-ascii?Q?Bgqkkc8yHTCZ7CEGzT2/jHjDOMhBJL9+iRha7xOHlZofpUT07glUv2R9hSa9?= =?us-ascii?Q?DMDblldmRB7hJT4KoHw3aSYtFzrYvxrHEAsGSb8ceUxcEvYG4mswjyRxDhZN?= =?us-ascii?Q?oxb1+JwBqOh3YjvjrK4fKbcqj8dJ10Cs2DnuDPLg?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 40c450cf-80f2-48d1-adda-08dba02010c9 X-MS-Exchange-CrossTenant-AuthSource: LV2PR12MB5869.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 18 Aug 2023 19:19:38.5303 (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: feWVmiJH76AaXzGbu/t7A9EkUQ0rdYPzQ9loDval4ij7oAIDwPqepmdDVwbzZj+j X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH7PR12MB8177 Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org On Fri, Aug 18, 2023 at 07:50:18PM +0100, Robin Murphy wrote: > > There is a difference between knowingly introducing new lockdep warnings > > into upstream and letting warnings discovered upstream rot for a while. > > Furthermore I'd say it's one thing to have deadlocks or warnings slip in as > part of some functional change, but quite another when the change is solely > reworking the locking in an attempt to make it better. This is clearly not > better. Exactly what isn't better? We now print a warning when pre-existing locking rules are violated. That is the only issue here. Jason