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Wysocki" , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Len Brown , linux-acpi@vger.kernel.org, stable@vger.kernel.org, Iain Lane , Mika Westerberg References: <20230710203319.GA220162@bhelgaas> From: "Limonciello, Mario" In-Reply-To: <20230710203319.GA220162@bhelgaas> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: SN6PR01CA0007.prod.exchangelabs.com (2603:10b6:805:b6::20) To MN0PR12MB6101.namprd12.prod.outlook.com (2603:10b6:208:3cb::10) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: MN0PR12MB6101:EE_|CO6PR12MB5393:EE_ X-MS-Office365-Filtering-Correlation-Id: 1dbb3194-80ca-416c-eb1d-08db819702d3 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:MN0PR12MB6101.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230028)(4636009)(396003)(376002)(136003)(39860400002)(346002)(366004)(451199021)(36756003)(86362001)(31696002)(38100700002)(478600001)(6666004)(45080400002)(54906003)(6486002)(966005)(6512007)(8676002)(316002)(5660300002)(2906002)(4326008)(66556008)(6916009)(66476007)(66946007)(31686004)(41300700001)(8936002)(2616005)(66574015)(26005)(6506007)(53546011)(186003)(83380400001)(45980500001)(43740500002);DIR:OUT;SFP:1101; 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Where is that? "Modern Standby" doesn't mean > anything to me, but maybe there's some spec that covers it? https://learn.microsoft.com/en-us/windows-hardware/design/device-experiences/modern-standby It quickly devolves into Microsoft specific stuff though and I can't find anything interesting to our specific issue. > Maybe this is the clue we need. My eyes glaze over when reading that > section, but if we can come up with a commit log that starts with a > sentence from that section and connects the dots all the way to the > platform_pci_power_manageable() implementation, that might be a good > argument that 9d26d3a8f1b0 was a little too aggressive. Yeah. > I like the fact that v5 ([1] for anybody following along at home) is > very generic: > > @@ bool pci_bridge_d3_possible(struct pci_dev *bridge) > ... > + if (pci_pcie_type(bridge) == PCI_EXP_TYPE_ROOT_PORT && > + !platform_pci_power_manageable(bridge)) > + return false; > > My objection was that we didn't have a clear connection to any specs, > so even though the code is perfectly generic, the commit log mentioned > specific cases (USB keyboard/mouse on xHCI device connected to USB-C > on AMD USB4 router). > > But maybe we *could* make a convincing generic commit log. I guess > we'd also have to explain the PCI_EXP_TYPE_ROOT_PORT part of the > patch. OK, I'll take a stab at rewriting the v5 commit message to be more generic as you suggested as a v7. We might be able to drop the PCI_EXP_TYPE_ROOT_PORT part well but I would be more worried about regressions from this.