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Thu, 12 Mar 2026 19:54:01 +0000 From: Dan Williams Date: Thu, 12 Mar 2026 12:53:59 -0700 To: Dan Williams , Smita Koralahalli , , , , , CC: Ard Biesheuvel , Alison Schofield , Vishal Verma , "Ira Weiny" , Dan Williams , Jonathan Cameron , Yazen Ghannam , Dave Jiang , Davidlohr Bueso , Matthew Wilcox , Jan Kara , "Rafael J . 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 , Smita Koralahalli , Tomasz Wolski Message-ID: <69b319d7e6adf_213210086@dwillia2-mobl4.notmuch> In-Reply-To: <69b1e0aacb9d0_2132100c5@dwillia2-mobl4.notmuch> References: <20260210064501.157591-1-Smita.KoralahalliChannabasappa@amd.com> <20260210064501.157591-4-Smita.KoralahalliChannabasappa@amd.com> <69b1e0aacb9d0_2132100c5@dwillia2-mobl4.notmuch> Subject: Re: [PATCH v6 3/9] cxl/region: Skip decoder reset on detach for autodiscovered regions Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: BY3PR04CA0001.namprd04.prod.outlook.com (2603:10b6:a03:217::6) To PH8PR11MB8107.namprd11.prod.outlook.com (2603:10b6:510:256::6) Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PH8PR11MB8107:EE_|MW3PR11MB4555:EE_ X-MS-Office365-Filtering-Correlation-Id: 7ea2912f-6929-49ae-2f69-08de80711b63 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|366016|376014|7416014|3122999024|18002099003|22082099003|56012099003; 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Then think about whether this needs a way to specify > "skip decoder teardown" to disambiguate "the decoder is disappearing > logically, but not physically, keep its configuration". That allows > turning any manual configuration into an auto-configuration and has an > explicit rule for all regions rather than the current "auto regions are > special" policy. Do not worry about this paragraph of feedback. I will start a new patch set to address this issue. It is the same problem impacting the accelerator series where driver reload resets the decode configuration by default. Both accelerator drivers and userspace should be able to opt-out / opt-in to that behavior. This will want some indication that the root decoder space is designated such that it does not get reassigned while the driver is detached.