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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?4NhcLP18lkgx2yuHaWSxq2GXzU8ejaN3V5Q241W3x+IRL89VxPf+l91JGi1v?= =?us-ascii?Q?Oh3gBiiyGGTgWcVV3jRVdvknFexVg/CUrjiM0PK2OT4oVh9geAzWxzxSgr1Z?= =?us-ascii?Q?EOnrMxBJVl3k5Z+q6Grp9pYJelbS1holnhi+Dx+zPVKW223hKWHNw2mPU3eJ?= =?us-ascii?Q?dbTAD85eRy99DU3BvXysskf8BhoZFxShJXEXE3ExoFBdCa0PoB8jcLe/D7Lo?= =?us-ascii?Q?bgjfe9P3RYBSQNL2mxKCobHCjGTBYShiaQvqvkPJEaLqreCm4LKglgS3wTzo?= =?us-ascii?Q?33TuTu896gylDGFkoueVFSop+lP5m7EBHSADqYbv00s/CQkwA8hxP/jmLWP8?= =?us-ascii?Q?mBHzAKPRaTMyJ8bW99cpMsWqB/OnRsauschgG84bZtCJmtsKsNDRmdakhbgh?= =?us-ascii?Q?3pjD0Ln4Z1WCJii0WPmWMLUJCoqPgzLxn1hQ3tErNRfMUfUod6UylVg44KQQ?= =?us-ascii?Q?9chB4Sjk0rvRPC2lI2hUwgH/k8fClgSEsATuLeaizkAui4JeSDZpBFhp9KVF?= =?us-ascii?Q?m6NmIsvfUOpyEZzihC770dNCLmsvlvrKVhZ/jVKp5KjUoRlxQ4yPc4O+dKkF?= =?us-ascii?Q?iQTUh6rEVHG/sAHT0aflRZEf0kSAFUy28sfv+dw0l2RdvpJUqZcCbtOwlAb6?= =?us-ascii?Q?mtD1lzFfHnq8uvESwWFhfOs1glrbkhU3uWsHpC+RC4d1ISIOWlgT5i6XuszU?= =?us-ascii?Q?yzmPDkKpWPGgdYKnfqfZkASrRCuQwiNvupeTOkbeh4WaExfS6nBUpBgVurW9?= =?us-ascii?Q?5vGbqc/zAO5Tcddegi69uERsgroPJUXudR+OJ67vEXDoXK3sm/dQtAf9kb+H?= =?us-ascii?Q?tN5YQ/fafGOJbAb7nLDS+4bP9CbLvel6fV/KYIIaRtowVOsbB0BNKrhDdZ/C?= =?us-ascii?Q?1Zix5N5pTAHzELNHaVJWjskVpxcXXQ5/yXBSGVrFB4Y1JdvSBYUZr05+I3LN?= =?us-ascii?Q?znlF8kHQqLbslEjoPmN/rWwadhU0gQAwTJPSF6GAPQ34EB/8WDHW+MMGRz+I?= =?us-ascii?Q?q667iU5imZ8ZLQnmcJqjTBqfGbN77JnZnOW3MPcFP+dB9o9CA34dC5YPIsIW?= =?us-ascii?Q?0a4MS3fl6gjTJVAKVFoI4cFlok32LkvYR4GiraSMVkOosoUe7mLZXJfAPeP8?= =?us-ascii?Q?4SmKOwx7FFHjB2/lJuAIoUXJ9Ju64QOtIoECngwQrqMdFHEHgu3JwjqEqYs+?= =?us-ascii?Q?5sIIZonlYGuy0s9X099sypkM1WCVyj4v8ripVByGGRVWL3nmUHqpbWWQPwP6?= =?us-ascii?Q?LWRIDFvMvliMlhJOQknDsc3ZC80jE8lCticaVCVbb+GvRxoB7fzTWVWPR/iR?= =?us-ascii?Q?IIueO0wleyKm5asNxFPFzcHVqRvepXX+30LHreqGDlSoQO3tCA6LaGN3otCG?= =?us-ascii?Q?7jhYa1mi7psYmSIkwV2KltJwRtf5wyBCcd4s/B68zSbyaSmDKj1Q2/FNPyqv?= =?us-ascii?Q?sokyoSa41Q5UYyVXJjavQ5j6kXdBg1uzXecIQXvYS4guPJiw0LC0GugDGRcv?= =?us-ascii?Q?Fz3+ZR/3+OTdgcAdXvdmYLH33MuKbP8VB2NbTTflnj2E00iGxhPSQocilaY7?= =?us-ascii?Q?pCykdmylZU38ITnE76PBJOOaBcr4hDCXm+78zFLV87hQE1pwUZ6ODQ1Oq9Mn?= =?us-ascii?Q?Zp1wajUai2srdNTOUUEBJKBjEBFa2rK6yi5DuWmZ7YRZ1f5SlmP8UhmKBi2j?= =?us-ascii?Q?KWKa4l3KT1ySy3PGKxfqOD9IW17iM0D5qd21qmW+p0ukhIZgoqalWTGt/dSy?= =?us-ascii?Q?ICzdUXGLRQ=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: f9e54a1a-e93b-40e3-7766-08da12812288 X-MS-Exchange-CrossTenant-AuthSource: MN2PR12MB4192.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 30 Mar 2022 19:11:46.7358 (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: u5iV6XWfUvyvMVWFdNZtyRMJJ7Csw8zRDdQHTkCFO2SQnc3d+11kXy1gPELHew+u X-MS-Exchange-Transport-CrossTenantHeadersStamped: MWHPR12MB1405 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Wed, Mar 30, 2022 at 02:10:17PM -0500, Bjorn Helgaas wrote: > On Wed, Mar 30, 2022 at 12:37:20PM -0300, Jason Gunthorpe wrote: > > On Wed, Mar 30, 2022 at 05:08:23PM +0300, Shlomo Pongratz wrote: > > > @@ -350,7 +353,10 @@ static struct pci_dev *pci_host_bridge_dev(struct pci_host_bridge *host) > > > > > > if (!root) > > > return NULL; > > > - if (root->devfn != PCI_DEVFN(0, 0)) > > > + > > > + /* Is it a host bridge or a root port? */ > > > > This is a better comment: > > > > /* host bridges must have a 0 devfn, but some of the entries in the > > whilelist are root ports that can have any devfn */ > > Is this something in the spec or is it just common practice? The PCIe > spec says very little about "host bridges" and I don't remember > anything about them having to be devfn 0 or even that they have to be > materialized as PCI devices. I think we are relying on common practice here, but I don't know why this check was added in the first place? Logan? Jason