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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?mE5R49gWTgTNDoqUd0lAG3WPLU+Y9VlcHEQ/TeP1f3dcGdpRs4rWHXERxR2n?= =?us-ascii?Q?Pci6Z6QHzOM5SJ0V5ugLkpTurIA9I/1LeiYv73eKfiZH/A4rL02mz787o/Ar?= =?us-ascii?Q?UBHovKDJJMNKwtJVn9KhjpYL9UtRPtaY9xpm3DqDSRPEgrd7gxytGm72qJRa?= =?us-ascii?Q?f4VJjO0E/tVGYkCz35x5I/ViKQf/aZlwMmbRfqn/i3bj2v2GYpCVkfLsGCde?= =?us-ascii?Q?D3AOd1CqFk2b8N50Iz/mydrPhum6I+5ajfDOikJfYjydIuGLZJiKWMk3O7hM?= =?us-ascii?Q?FMW9R5qq2Z2RXJy3HNNq4eUm3kdZqEqj4j0W5W2WEMSNfIiZ13rVoJ7dp0uD?= =?us-ascii?Q?V4KFBMiO6nEqg/5KgPrI35HjZ0lToYFIenHmxbJN+sizj0H3dVFlpzCr8wQT?= =?us-ascii?Q?wuzRGShIX6BPtjpvIRvS0hRDq4/eA7BRDq4X4EV1VW5klG9g1mlIBPdgPTE2?= =?us-ascii?Q?TdEkfSKV3ZCHOIa6DKOE2KW2Cdu+w5rhny3Vepqmzu+xJR4onJ8A2uu1/khz?= =?us-ascii?Q?+5md+1v0mQkgAF12iNzWipCZtUp+gbL4XNtpX5gQ/EbU49lImCHfWbL7D484?= =?us-ascii?Q?o+Xt60qT0QPh78gR5eA1AAeiTRGcQptAvGEqpJ62wR+N7OVEbQzgYcBkyxSH?= =?us-ascii?Q?vDR58O2T7CHGrhl0Mmcu6WxzgtQEl9fg2feh+8Y7+v03iG8yfy5MvtIq1gXa?= =?us-ascii?Q?OvpfMOobKbn2u7k/AxXDWoLFcisiqZOl3w3gSX0I82/M9UlMRNMBv9ufRW01?= =?us-ascii?Q?9llBCBXBZlLpcVoyP78//cXvsyfDlHuU6UQGUQpB54yiFNS7fmQhbOwf9G26?= =?us-ascii?Q?ei2yj2ovY2T3RRcekwXjcC/EiM9Uv/BBxU3X0PDOZ78sjA5GhBde1tkmOHLI?= =?us-ascii?Q?XgFsWoaYNFNmlY4hcJ5VsUX7kiwk3NYTa4rj5uKQlZS0q338HujVZ5q1SqiP?= =?us-ascii?Q?eewZIQjKW/VltvQs5GuSN88sNQNr1nRzUk2cr/wd0Jz5B4uV8tf0/L4StM70?= =?us-ascii?Q?Idu8yX20ijqf+G3WSd30qnh2bqHTX7rkRQ5fCUpfsXIo+biEzGLAKf5VT8jy?= =?us-ascii?Q?RBua/ECimjTc3qFswHXQ9ajZVPAAVbc6A/jevapO/VzBeQTI3s+d8/k95qNt?= =?us-ascii?Q?M74ZnEOd+1kFdRXW9VCMQyL0jueYcsCOmXQYRWCUN1ZhfGcka0J2JcCOml4p?= =?us-ascii?Q?XZwwR0MmJ/EN7RANewmR//R3deOeQ4CvO/es7Uy3xI7r7tQu3+XFR9My0yXe?= =?us-ascii?Q?Ij6OIYx+2XtOy1Frb9csvQ2msQiVaXQNmC4rHz0p7+uEGxNCkFvYa/cKrG5Q?= =?us-ascii?Q?qKL1I4F6fkUfnUvU+zHY7Ll1jEDX/j52nW+/0hDFbTcSMDEKn+JyvJi18wt3?= =?us-ascii?Q?xtwBlz6TE7Mfplxv1k2we0UXOAUseng8cm2NHm/CndcwP8Fn3NvCrnU2NlTX?= =?us-ascii?Q?avs/4pkPMDRjnFG9VTUoewyfR36fKLqK1Nid6mONiHQfUw+XM1QxbyyuZYwi?= =?us-ascii?Q?4MFXCh9zMrIQVbFVKHaRfoj1y86E/oQBNoC9u1bBGIg30iXXxf77byOSxTdC?= =?us-ascii?Q?GUJC7RTR+r7sIRE9Sftx/3z3Bk46rjvFAcntwpZ6JL9feD4C8H/R9SH4zM5b?= =?us-ascii?Q?9Q=3D=3D?= X-MS-Exchange-CrossTenant-Network-Message-Id: 85d12d17-8fe9-4e3a-1f22-08dbeba403db X-MS-Exchange-CrossTenant-AuthSource: PH8PR11MB8107.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 22 Nov 2023 21:43:07.6066 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: cLo4DhvheGUgiEMHRXNfvG2qJkUPJqPBEiei78mqmOgqxK0IXhiTOnuSuMYCyU1AXhOji7o0xMI02GgmvJZ8ug/pSEVYH2atUbbT0KI6OFY= X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA1PR11MB5875 X-OriginatorOrg: intel.com Davidlohr Bueso wrote: > On Fri, 17 Nov 2023, Dave Jiang wrote: > > >init_hdm_decoder() modifies port->commit_end without taking the > >cxl_region_rwsem. An assert splat emitted by cxl_num_decoders_committed(). > >However looking at the code, it looks like the write version of the rwsem > >needs to be taken due to the modification of commit_end. Wrap the write > >version of the rwsem around reading and writing of commit_end. > > > >Fixes: 176baefb2eb5 ("cxl/hdm: Commit decoder state to hardware") > >Signed-off-by: Dave Jiang > > Uhmm but do we expect concurrency during the switch/port probing phase? I answered that that detail here in response to Fan: http://lore.kernel.org/r/654eb8ed72ced_46f0294c@dwillia2-mobl3.amr.corp.intel.com.notmuch The takeaway is: "I am in favor of adding the locking rather than depend on a subtle side-effect of how CXL operates, and to avoid adding an unlocked version of cxl_num_decoders_committed()" I will add a note to the changelog to that effect, and drop Fixes: since the lock is not strictly required for correctness in this path.