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Wed, 11 Mar 2026 19:35:32 +0000 From: Dan Williams Date: Wed, 11 Mar 2026 12:35:29 -0700 To: Bjorn Helgaas , Keith Busch CC: , , , , Keith Busch Message-ID: <69b1c401a109b_21321009f@dwillia2-mobl4.notmuch> In-Reply-To: <20260309205009.GA582379@bhelgaas> References: <20260217160836.2709885-3-kbusch@meta.com> <20260309205009.GA582379@bhelgaas> Subject: Re: [PATCHv5 2/3] PCI: allow all bus devices to use the same slot Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: SJ0PR05CA0036.namprd05.prod.outlook.com (2603:10b6:a03:33f::11) To PH8PR11MB8107.namprd11.prod.outlook.com (2603:10b6:510:256::6) Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PH8PR11MB8107:EE_|IA1PR11MB7775:EE_ X-MS-Office365-Filtering-Correlation-Id: e6c3053a-f158-4b54-aa03-08de7fa55bd4 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|1800799024|376014|18002099003|22082099003|56012099003; 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Thus, pciehp > > only allocates a single hotplug_slot for the bridge to that bus. The pci > > slot, though, would only match to functions on device 0, meaning all > > device beyond that are not matched to any slot even though they share > > it. A slot reset will break all the missing devices because the handling > > skips them. > > I tweaked this a bit to (a) refer to the "secondary" bus instead of > "subordinate" to avoid confusion with the PCI "subordinate" term > ("pci_dev->subordinate" already has this confusion but is harder to > fix), and (b) mention ARI, which I think is what causes the problem > you're solving: [..] > Let me know if I got any of this wrong. Looks good to me and matches my understanding of what Keith is fixing.