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Mon, 30 Mar 2026 22:36:16 +0000 Date: Mon, 30 Mar 2026 15:36:07 -0700 From: Alison Schofield To: Alejandro Lucero Palau CC: , , , , , , , , , , Jonathan Cameron , Davidlohr Bueso , "Ben Cheatham" Subject: Re: [PATCH v24 10/11] cxl: Avoid dax creation for accelerators Message-ID: References: <20260323113117.2352709-1-alejandro.lucero-palau@amd.com> <20260323113117.2352709-11-alejandro.lucero-palau@amd.com> <8737035f-07e9-4c14-93a9-bb542197d7f7@amd.com> Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <8737035f-07e9-4c14-93a9-bb542197d7f7@amd.com> X-ClientProxiedBy: SJ0PR03CA0245.namprd03.prod.outlook.com (2603:10b6:a03:3a0::10) To DS4PPF0BAC23327.namprd11.prod.outlook.com (2603:10b6:f:fc02::9) Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS4PPF0BAC23327:EE_|MW3PR11MB4523:EE_ X-MS-Office365-Filtering-Correlation-Id: ba18c84b-b503-493c-aaed-08de8eacc153 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|7416014|376014|1800799024|22082099003|18002099003|56012099003; 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The point really is that this skips 3 things, not just DAX creation. So, address each of those things in the commit message, or narrow what is skipped to be only the DAX creation. see below... > > > > follow me ... > > > > > Signed-off-by: Alejandro Lucero > > > Reviewed-by: Jonathan Cameron > > > Reviewed-by: Davidlohr Bueso > > > Reviewed-by: Dave Jiang > > > Reviewed-by: Ben Cheatham > > > --- > > > drivers/cxl/core/region.c | 7 +++++++ > > > 1 file changed, 7 insertions(+) > > > > > > diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c > > > index 8bb53a095290..2f9bdb4f1f4f 100644 > > > --- a/drivers/cxl/core/region.c > > > +++ b/drivers/cxl/core/region.c > > > @@ -4263,6 +4263,13 @@ static int cxl_region_probe(struct device *dev) > > > if (rc) > > > return rc; > > > + /* > > > + * HDM-D[B] (device-memory) regions have accelerator specific usage. > > > + * Skip device-dax registration. > > > + */ > > > + if (cxlr->type == CXL_DECODER_DEVMEM) > > > + return 0; > > > + > > And above says 'Skip device-dax' specific again, and is indeed skipped. > > > > This escape is not surgically placed at the point where dax is added. > > We are skipping a few other things before dax registration actually > > happens. Why skip memory notifiers, shutdown_notifiers, poison setup? > > > posion setup crashes with a type2 and I'm not sure if the memory notifiers > make sense for Type2. > wrt - poison set crashes with a type2: Let's not leave a known crash to be tripped upon in the future. The crash is probably on a dereference on cxl_memdev_state, mds, which you guarded against in Patch 4/11 in other paths. I think this needs similar check added to cxl_memdev_has_poison_cmd(). With that, I expect the cxl_region_setup_poison() in this path here. Success meaning it looked to see if it's member devices supported poison, they do not, so no poison set up. I'm not familiar w the notifiers. > > If it is really needed, I would prefer to support it as a follow up. > > > Thank you > > > > > > > /* > > > * From this point on any path that changes the region's state away from > > > * CXL_CONFIG_COMMIT is also responsible for releasing the driver. > > > -- > > > 2.34.1 > > > > > >