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Wysocki" , Len Brown , Pavel Machek , Li Ming , Jeff Johnson , Ying Huang , Yao Xingtao , Peter Zijlstra , Greg Kroah-Hartman , Nathan Fontenot , Terry Bowman , Robert Richter , Benjamin Cheatham , Zhijian Li , Borislav Petkov , Tomasz Wolski References: <20260122045543.218194-1-Smita.KoralahalliChannabasappa@amd.com> <20260122045543.218194-4-Smita.KoralahalliChannabasappa@amd.com> <20260122161858.00004b0c@huawei.com> Content-Language: en-US From: "Koralahalli Channabasappa, Smita" In-Reply-To: <20260122161858.00004b0c@huawei.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: SJ0PR03CA0201.namprd03.prod.outlook.com (2603:10b6:a03:2ef::26) To LV8PR12MB9714.namprd12.prod.outlook.com (2603:10b6:408:2a0::5) Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: LV8PR12MB9714:EE_|DS0PR12MB7971:EE_ X-MS-Office365-Filtering-Correlation-Id: 46c5e059-8b6d-4a14-d9b6-08de5d2320f6 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|1800799024|7416014|376014|7053199007; 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For >> autodiscovered regions, this can incorrectly tear down decoder state >> that may be relied upon by other consumers or by subsequent ownership >> decisions. >> >> Skip cxl_region_decode_reset() during detach when CXL_REGION_F_AUTO is >> set. >> >> Signed-off-by: Smita Koralahalli > Reviewed-by: Jonathan Cameron > purely on basis we should probably not undo things we didn't do in the > first place. > > J Thank you! I’m re reading Dan’s note here: https://lore.kernel.org/all/6930dacd6510f_198110020@dwillia2-mobl4.notmuch/ Specifically this part: "If the administrator actually wants to destroy and reclaim that physical address space then they need to forcefully de-commit that auto-assembled region via the @commit sysfs attribute. So that means commit_store() needs to clear CXL_REGION_F_AUTO to get the decoder reset to happen." Today the sysfs commit=0 path inside commit_store() resets decoders without the AUTO check whereas the detach path now skips the reset when CXL_REGION_F_AUTO is set. I think the same rationale should apply to the sysfs de-commit path as well? I’m trying to understand the implications of not guarding the reset with AUTO in commit_store(). Thanks Smita