From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 52DF52E40E for ; Tue, 2 Dec 2025 21:35:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=192.198.163.12 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764711321; cv=fail; b=PsRchanCeAv7zIODJggB37ySiLP+I9fNuE07QafIIut9M2DTUBcFCYn+HEeBbocIRxU31bd88U13D5YogicAvspulfLxSTJSJ01XbHcU9Y6gNmXw8LPCdIBv+YEv3QHMbVpavQMDYilyKuEYKPjIUOmR1KTDO7XmuWxmOMDlKeQ= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764711321; c=relaxed/simple; bh=Wo2y4y+levO41UEmmgSbcfzLMuoWeSbWPQqFRBRLTAs=; h=Date:From:To:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:MIME-Version; b=o8jNbgRNgJkQckx7UdqWJMS8uBALuxyXvIu9PsBiwgEgBLgFVc0lj9NNbdNFXm6oZynJ7wiGRwMTTLmEoaYga2ROnbakgO+SLNJqC5VikK+NK7hplE63Bw90xicp6h9TwbAzoT8r8SNrxLi0JiqoGEknLtSJwBEn2ePl6SE3eIQ= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=LvxX8IJE; arc=fail smtp.client-ip=192.198.163.12 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="LvxX8IJE" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1764711319; x=1796247319; h=date:from:to:subject:message-id:reply-to:references: in-reply-to:mime-version; bh=Wo2y4y+levO41UEmmgSbcfzLMuoWeSbWPQqFRBRLTAs=; b=LvxX8IJErVa6HKe4G+RH32TQThJbhbWuJAIFOCLGKqbFQkC6Q0vuRhMQ sMgME+Qmc2tmSufxoHiBLGSFpN1FFaq7JN2pN+lk/ksGohoAy4wjDk2Gc X0v+4RcPo0zM63aSkjmVh79Nrzvf0Zw0u9tVUOGgRUI9PT6eNbrqEfXbP 92Oeisb79H42JoTb1Yw1nEWxS4bP02YEL0ZndEAn4ZlXX/ZcN87GSz51n siZx4j/3EjsxqaJMQk1S6+thQjK+Bri+vgOLZLDjMnDc7JsJVAQUbzkGJ Fnf8ZQp/ewy0x4z+o9U+rzCQ4MhWZaST5hxuaNid8AbWkGo4wM23/5iuS A==; X-CSE-ConnectionGUID: GSHshtX/Q3OKuJlg50jj/g== X-CSE-MsgGUID: VjuWn1cGS7iWa0n9BDHOZw== X-IronPort-AV: E=McAfee;i="6800,10657,11631"; a="70547310" X-IronPort-AV: E=Sophos;i="6.20,244,1758610800"; d="scan'208";a="70547310" Received: from fmviesa002.fm.intel.com ([10.60.135.142]) by fmvoesa106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Dec 2025 13:35:19 -0800 X-CSE-ConnectionGUID: pnzsI74zR9ixG7c6X3ecLg== X-CSE-MsgGUID: 6m24ZgwQRYG1BqAxuu76IQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.20,244,1758610800"; d="scan'208";a="217839097" Received: from orsmsx903.amr.corp.intel.com ([10.22.229.25]) by fmviesa002.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Dec 2025 13:35:18 -0800 Received: from ORSMSX902.amr.corp.intel.com (10.22.229.24) by ORSMSX903.amr.corp.intel.com (10.22.229.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.29; Tue, 2 Dec 2025 13:35:17 -0800 Received: from ORSEDG902.ED.cps.intel.com (10.7.248.12) by ORSMSX902.amr.corp.intel.com (10.22.229.24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.29 via Frontend Transport; Tue, 2 Dec 2025 13:35:17 -0800 Received: from DM1PR04CU001.outbound.protection.outlook.com (52.101.61.53) by edgegateway.intel.com (134.134.137.112) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.29; Tue, 2 Dec 2025 13:35:17 -0800 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=INNeeeoojhLxZA+Tbrz72IIYrzm1YAXsH/w5+GfX8a67Y6luuMF0pgzEhKti6UxSC1cQnT/jQQioc5L/0QoKlOE+BeMtsBupWWKdQVvP2i70HYe3kjFMuTKqBNBryHPX9OZSSNNFMzTBq/OhejlCOfYekRAzxpeyxl7vUKZone55/bAa7+Zqwo6VM/Mf3hOr/nD+0SOa6NN0Aq3QRwvTG3xUPkzjgHBZaiUCwI8BUF9ipwkt9RUX5DZiwK02Fb3wPDSDcKwoHg3qC/z2oUgnvQoKhDmF0Th4APu9fQzVxwKY/kC2yEGr3RrlOx1oiZFWhKD9FXQac9ancW6aOQjxPQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=o7YzIQvbeG3vxFBH3Apq7k1+0yOqL6+bri9z/CqhPB8=; b=RarN4qB7MJU6l0hP3insu0djlGmX1TU6Bx4h04bnO1GB+vjdJI8pOuHcduQ7qptK74Ckj6/0VezTTdFEJHxvoy/xOQ4UKOIfp6p2Z6it6NJz0iJxa5MmI6g3FempKlUdFpMMcmyD0w4CED731LsTUrgEm1sFuKfXTVMqpXwEeLBGY05fMMZTIROfKrqmpRruCLl3pAJ8kmYSg4p29K2BCdN3SE9c3rzbh70otFih8AhqGMl3Rjetp4efcJOFu6J3DONygVUKf/uRt8YS7HMgGxbYltZ2AYOsW5bfgCKszln1oNfe2/Egq47C+SmHkL6tvQ2nTM2TcaZo1eOn4v51Fw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=intel.com; dmarc=pass action=none header.from=intel.com; dkim=pass header.d=intel.com; arc=none Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=intel.com; Received: from SJ0PR11MB4845.namprd11.prod.outlook.com (2603:10b6:a03:2d1::10) by DS0PR11MB7312.namprd11.prod.outlook.com (2603:10b6:8:11f::18) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9366.17; Tue, 2 Dec 2025 21:35:16 +0000 Received: from SJ0PR11MB4845.namprd11.prod.outlook.com ([fe80::8900:d137:e757:ac9f]) by SJ0PR11MB4845.namprd11.prod.outlook.com ([fe80::8900:d137:e757:ac9f%3]) with mapi id 15.20.9366.012; Tue, 2 Dec 2025 21:35:16 +0000 Date: Tue, 2 Dec 2025 23:35:11 +0200 From: Imre Deak To: Jani Nikula , , , Mohammed Thasleem , Subject: Re: [PATCH] drm/i915/dmc: fix an unlikely NULL pointer deference at probe Message-ID: Reply-To: References: <20251202183950.2450315-1-jani.nikula@intel.com> Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: LO4P123CA0075.GBRP123.PROD.OUTLOOK.COM (2603:10a6:600:190::8) To SJ0PR11MB4845.namprd11.prod.outlook.com (2603:10b6:a03:2d1::10) Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SJ0PR11MB4845:EE_|DS0PR11MB7312:EE_ X-MS-Office365-Filtering-Correlation-Id: e385e41f-8c42-4ebb-5e13-08de31eaaefa X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|10070799003|376014|366016; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?AYrwZM73XWUtskeohf/EeDrhAguOvdhMc9RfnA3HaEzenyZyAwQi0S3PqSEE?= =?us-ascii?Q?/9ZqFYLCth9NSfH4X64QcidrEX8k+enc4JZ7hOjKVCNM3JjBigjL4V1q9P9a?= =?us-ascii?Q?RJPUOAh2Z1rsQzyfjZ1IlO3sJUp/wheV9CdjCEUhUUndzv3igZ/iTxYppEKm?= =?us-ascii?Q?AIKXH28jok2HsYb9i8K/vJBlhIO7Avr/og+BwPlTS/1xC/j3w0bM12SOlbL1?= =?us-ascii?Q?+4RxVexzqC9WKWBxy8TQFlVbEqzoLZZjavlDJz34TpezW2nYEsJ5LRyd6OS0?= =?us-ascii?Q?/JUnIaQlJC0/ne4TuqjkUhVfe20fOXQCng/zbfSZHudGr6YnN+9ExkDTgGBm?= =?us-ascii?Q?gLod4M5RADGPzxvpMxVcoF5IHdSHlYR81yFDttf2Q1w6XC8qmigM9Js6WlLz?= =?us-ascii?Q?geJD9MiqEAlAu9Ir+d1NCmoPlFUYKGpv9/PcD/BM1HSVmu36nDpc+RafDqpQ?= =?us-ascii?Q?pXLnyHL1XwPcMQavWPKkriGYIWSqQU0Dx14387xvz1kOYeX/CIisuiq0Yjwt?= =?us-ascii?Q?GGp40tHwlu+3djf22C8YikjAAbmHvZEhA8KUP7p5zPglIL7nPcTMbuBku25w?= =?us-ascii?Q?2n4yIKW5Tt7g3EKpu+k8UyZzy3mUyWrUogPPUnliJNUr5TONFsimHfXFGKsY?= =?us-ascii?Q?VYSOV1f2o2kBQ7t8fJROVV1QxZxCvBxEROoXOrH1eT3/xLi6+Mqw66kLaoDC?= =?us-ascii?Q?OUVBWd+hTTpUDcquNPgfoKRvqEhrL/mCF0HQol/n8t7XSmdKxJcHvVVXNczH?= =?us-ascii?Q?EQRvG4+GZxEPSs55s/CDGfc+HbUHoSmRoJRoFMYwmm4ukm0ifeSyuInS84My?= =?us-ascii?Q?ZWGgu/jQ2enQFD+6Yr5Co5QFCFKwyRwptruV5JRiym8Ytt17QaMUSwAFduNf?= =?us-ascii?Q?AWSUYq0RJ0EjvrnKAX0XOGYjqExBatCWhMt/1FkX3tJZQJiVuVd/awqmgffz?= =?us-ascii?Q?seD89QKd12CuW1o8fQSPVJp/InAAQI/N4/AOSSaaZ8GT7c6cqi3QkagMaA/J?= =?us-ascii?Q?ifgkU3xWh0TYaandsoZg3FsqzKvFFUN0tqTwKrdHaF+/0Zg83pay5E6d3x1n?= =?us-ascii?Q?2wJWwzsvuzXUzCilcUH2MptqA0RHfDXOpLJu9m7c6PYmj1WUMbBBkfada9Aj?= =?us-ascii?Q?sHv6Ef01ddvE4441wxokNlKCmR7mA7zG5p2NLabiELR+HbTKNPB2bklpPipV?= =?us-ascii?Q?uy8jqy4fFt0EE08iUiQ8iEqZv5MRD/d+iOMi3smJkgli20ssbwrhMbczZrdo?= =?us-ascii?Q?gx1f2ZmGNs+xiLN7aZt/b2N4O3R5nUWAolrewNCVlvaNFGcxVHV1CsOrr1Ax?= =?us-ascii?Q?BTY+IbvuamUTwr8Z556P2bMrvCjpyCdTBCgJOsORT4eJXel0/UrCRtGgtQa5?= =?us-ascii?Q?J1v2Z+g1LL08T3G2wpFYlSFzum9lj9vnMbCJu0C0/z8Z/yKSdlCmEsaZ3973?= =?us-ascii?Q?w+vtVPN0FtAfkUvQtkye/Nhn2xl7GV1m?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:SJ0PR11MB4845.namprd11.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(10070799003)(376014)(366016);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?jPOrYte6gEm7aOoDysHeFI57Zxoy11EFqruoGhTqBhLVpqXRJmEqIkng6qoD?= =?us-ascii?Q?dQAjBaCMgjDvzHoqu1j9Wz4IqTFe9MHw82r2TYFsTQ+InmwF+kZB8cBf4/ou?= =?us-ascii?Q?haKRZQAPd7cItfzv0m1EVIzrC3KmMJx4xTHzUvK/5TPim0+nYWiQI7QYLeFX?= =?us-ascii?Q?ReTeyoGIZBu0Js/rD+7UFc3/7h4BmpP1UU1sLH1UPrE/Bk8T6hoX6tkmyusS?= =?us-ascii?Q?HldJE5R2hTiIoDWhtxgm8wO17qWPpkvt0Tx/+srCur3QFbL+uh/SQIcjUM5k?= =?us-ascii?Q?yghW3JMqLlno8UG1f1BeoRCnQTVfcjoVVIwNLgQgOOUyFIHrT3Kf/YunOXc9?= =?us-ascii?Q?ffIj8XET5FQSGObmRK34YBF4JN7CwHaV9NiEYr19TxkSDmCFKzRwwyfFqtAN?= =?us-ascii?Q?D/pcdWxLJ+nzCO63Zcw9dy7PNnjZlVolyZkIFTSg7NwUXpqOhhCiKHBPNUR6?= =?us-ascii?Q?o8ssTs7WxQtu9/qUBncThcn2+1wsipNb5KtetUwaZjctRhOnIw3ygN1b0i0W?= =?us-ascii?Q?+ZxOA5LqfGZ1hqQl5i5lEwgBUKV51cU1U6LJYkY0Pq+TNEiI3w6yfHzlnWI0?= =?us-ascii?Q?gk0bD1SLS4jd4erR2vs56evr090zqnmSpiqF6zeznMeO9sdQ9tLzanGrczMG?= =?us-ascii?Q?/St9nxs/CdWHYr8IYL1Bh11gqdAGkWNGTt/YjMl3+uhzprxLVvwcKI+yPa9d?= =?us-ascii?Q?r/aX7LamZ8EfFJnrk7/WWpyTmxigDQ0z+5F59aw3YWqZaRm2tuVrmbZ6SaOH?= =?us-ascii?Q?wHem2NUvWK9wLtZc7kQD/+/PCKUjo8FxLzpfDadx8YJVUJRXdRQd+NKq4kXN?= =?us-ascii?Q?lH15Cj6od9r4xyKjIIeJjXQs17ZfGQj1fQ4IRRpsg4S9ds6m3pUie9ibboTS?= =?us-ascii?Q?q2vu9h5XlComOAKSCnVZRzRfAQzUrxc28QV/4uPI7s8/NUOFzNO8x5uTV1yB?= =?us-ascii?Q?zicfsTqqYzi8YUtFC8Dxj5r2ea5NWsBIjiaabw3J+xnwlyCbyh3kMe07OYHM?= =?us-ascii?Q?zFN7LmBg0uJ32KZeWEjVO4WXxxSNDeU8sd+vJzZYOMSNrfSmh0Ij5S3UiPF6?= =?us-ascii?Q?Fx1Gagz1VuCSjfvkcZthI4LgKthy+qaHM4qo0Eo5gvbscw0llC7ir5ZOJSxm?= =?us-ascii?Q?E5MRgIqSgs9Pd9+nfZ0YATY/pi25P3bjW6bmEV5U63ztdg4Ty6NsbIa/J7RC?= =?us-ascii?Q?pk9M+r+5tnLALV2vpPKeurTumT3k6NDOT7vPuLeodUNgTYsHQ2CF7jXEnHAS?= =?us-ascii?Q?YogRSl/tis90GlDLN+vH4o6GNdwO4ylRuP9q5uaZCY9F4KWvZFNWuVK1Ljxx?= =?us-ascii?Q?89rNCbMw6MziJBF/RobsIx2kF198sYvh9nU6Tm9nCflpEno6ToyeThVcn2Cn?= =?us-ascii?Q?FYrRpy+bH7ItjfL2g4LXCCahPnLIGK9hD02E1E0RtsB5irMI9KJ9Cr2T0Py2?= =?us-ascii?Q?N9tE0NB7IcDJy98Vmox9zDsjX+3FBLC4IiB/FZGWTySfWr1A5DyRCRMBEPiK?= =?us-ascii?Q?+9mrXC2A0xCRwwWewAJRsu9ZEX4NUQ3jFSSFptfuAkxRw8imyLTG+myKL0oM?= =?us-ascii?Q?HObz5p1sceqtDWIJXK/ppz2Y1tjWJf8c0v9M8EeJR2gZYeKfuGIKaQk/SGUv?= =?us-ascii?Q?u5rci32kRsKpaTBPIakJeTF1NvUz8zb+X/cFRqqGTCSN?= X-MS-Exchange-CrossTenant-Network-Message-Id: e385e41f-8c42-4ebb-5e13-08de31eaaefa X-MS-Exchange-CrossTenant-AuthSource: SJ0PR11MB4845.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 02 Dec 2025 21:35:16.1725 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: beGh9YGHqgJD/OPEJxeocUE7bvMK1mI00V8vwtISvqhZIiPXrmfPfnBZ+x9z0IuBjAhwE7iRDnpGujwy82/3pA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS0PR11MB7312 X-OriginatorOrg: intel.com On Tue, Dec 02, 2025 at 11:24:42PM +0200, Imre Deak wrote: > On Tue, Dec 02, 2025 at 08:39:50PM +0200, Jani Nikula wrote: > > intel_dmc_update_dc6_allowed_count() oopses when DMC hasn't been > > initialized, and dmc is thus NULL. > > > > That would be the case when the call path is > > intel_power_domains_init_hw() -> {skl,bxt,icl}_display_core_init() -> > > gen9_set_dc_state() -> intel_dmc_update_dc6_allowed_count(), as > > intel_power_domains_init_hw() is called *before* intel_dmc_init(). > > > > However, gen9_set_dc_state() calls intel_dmc_update_dc6_allowed_count() > > conditionally, depending on the current and target DC states. At probe, > > the target is disabled, but if DC6 is enabled, the function is called, > > and an oops follows. Apparently it's quite unlikely that DC6 is enabled > > at probe, as we haven't seen this failure mode before. > > > > Add NULL checks and switch the dmc->display references to just display. > > > > Fixes: 88c1f9a4d36d ("drm/i915/dmc: Create debugfs entry for dc6 counter") > > Cc: Mohammed Thasleem > > Cc: Imre Deak > > Cc: # v6.16+ > > Signed-off-by: Jani Nikula > > > > --- > > > > Rare case, but this may also throw off the rc6 counting in debugfs when > > it does happen. > > Yes, I missed the case where the driver is being loaded while DC6 is > enabled, this is what happens for the reporter: > > i915 0000:00:04.0: [drm] *ERROR* DC state mismatch (0x0 -> 0x2) > > That's odd, as DC6 requires the DMC firmware, which - if it's indeed > loaded by BIOS for instance - will be overwritten by the driver, not a > well specified sequence (even though the driver is trying to handle it > correctly by disabling any active firmware handler). > > But as you pointed out this would also throw off the cooked-up DC6 > counter tracking, Actually the patch would keep the counter working, as the counter wouldn't be updated in the dmc==NULL case. However I still think the correct fix would be to check the correct DC state, which from the POV of the counter tracking is the driver's version of the state, not the HW state. > so could instead the counter update depend on the > driver's DC state instead of the HW state? I.e. set > gen9_set_dc_state()/dc6_was_enabled, > intel_dmc_get_dc6_allowed_count()/dc6_enable if power_domains->dc_state > says that DC6 was indeed enabled by the driver (instead of checking the > HW state). > > That would fix the reporter's oops when calling > intel_dmc_update_dc6_allowed_count(start_tracking=false), by not calling > it if the driver hasn't actually enabled DC6 and it would also keep the > DC6 counter tracking correct. > > intel_dmc_update_dc6_allowed_count(start_tracking=true) would be also > guaranteed to be called only once the firmware is loaded, as until that > point enabling DC6 is blocked (by holding a reference on the DC_off > power well). > > > --- > > drivers/gpu/drm/i915/display/intel_dmc.c | 6 +++--- > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/display/intel_dmc.c b/drivers/gpu/drm/i915/display/intel_dmc.c > > index 2fb6fec6dc99..169bbbc91f6d 100644 > > --- a/drivers/gpu/drm/i915/display/intel_dmc.c > > +++ b/drivers/gpu/drm/i915/display/intel_dmc.c > > @@ -1570,10 +1570,10 @@ void intel_dmc_update_dc6_allowed_count(struct intel_display *display, > > struct intel_dmc *dmc = display_to_dmc(display); > > u32 dc5_cur_count; > > > > - if (DISPLAY_VER(dmc->display) < 14) > > + if (!dmc || DISPLAY_VER(display) < 14) > > return; > > > > - dc5_cur_count = intel_de_read(dmc->display, DG1_DMC_DEBUG_DC5_COUNT); > > + dc5_cur_count = intel_de_read(display, DG1_DMC_DEBUG_DC5_COUNT); > > > > if (!start_tracking) > > dmc->dc6_allowed.count += dc5_cur_count - dmc->dc6_allowed.dc5_start; > > @@ -1587,7 +1587,7 @@ static bool intel_dmc_get_dc6_allowed_count(struct intel_display *display, u32 * > > struct intel_dmc *dmc = display_to_dmc(display); > > bool dc6_enabled; > > > > - if (DISPLAY_VER(display) < 14) > > + if (!dmc || DISPLAY_VER(display) < 14) > > return false; > > > > mutex_lock(&power_domains->lock); > > -- > > 2.47.3 > >