From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1CC7ECCA476 for ; Mon, 13 Oct 2025 07:29:00 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id AE87210E3D8; Mon, 13 Oct 2025 07:28:59 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; unprotected) header.d=amd.com header.i=@amd.com header.b="wks/i2YZ"; dkim-atps=neutral Received: from DM1PR04CU001.outbound.protection.outlook.com (mail-centralusazon11010033.outbound.protection.outlook.com [52.101.61.33]) by gabe.freedesktop.org (Postfix) with ESMTPS id 1C7CB10E3D8; Mon, 13 Oct 2025 07:28:58 +0000 (UTC) ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=Nur5BJerzXJNksEwTTlb0Lr00V+9fHKajjSy7Tp25toXTioOBun6EfFhDgpXVKFHqRvKpn5dUG4I/WcMzKx4J6jZUTt/Ch9n9cHcxXZZBE0Izvklci4L88tbkNscIl1v9GaBX+EC1hIv1k/ERRKkgJnm2TPoFjc80POb0Er8CR20gx4sp3oYn9Eo2T6L1Rr184sa0p2A4GA1FKAiNi/n6glpHPW2LYz58jZcjk5vNG/4OKckgEYlWd7onHsuK9jrGhxsjP9yEc8cD7+at8Bruo8nJpwzkhYaEynW6ri7xn7Ygphv7FG4VZsTu2NYr0XEV84hGZo+oNa08Y9xh/eVrA== 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=7t0/ghDLOdwjVaQJybLYZy56tfNj5ERhCpxI0+IUt/g=; b=gJ3V2jjXi0v7yr5nmzyQMHwZwUUeJWdMdAMubL6RSX9rFuuGPGRp1cgm7uZWbCkgbvw5kpmnDfQ8/OBhBe445tIcCF2IXFFeQ9NRLmCo1DtpvVIc4QPvjqd+7QUz0HQsV79eSTD0nqgKf0BMp/2y9QEZVjLdqqLPv7PVW5ubHS20sPvXVnbA7RXJl3V64yWaW/su1iiOAr9aRhzLDYimwUnFfAX7z3rEB6+giyTwzykYat7aPHVhGxH1exDysH+3ZUKpDooRHazhqBxf+k41uWtU3OClM8ReyfuCSiYl/vMTU3y4rtAU0wU0+dzrjRMtgRJwGuEgICymFaS3OE+SAw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=amd.com; dmarc=pass action=none header.from=amd.com; dkim=pass header.d=amd.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=7t0/ghDLOdwjVaQJybLYZy56tfNj5ERhCpxI0+IUt/g=; b=wks/i2YZYH6jwphogcEkFsfttuHUS0eoa437Csyo7ypRQcxFWuBd4SuQIkhIS3woT0gzJUg6djAUTzAaxRP++tFLx+Ts50raVdg3tuGyCTQXwjlJcBmF7JNrYvhJW68tydXoDs0CHfEghXiq/ScdVShPTgIcf7R7h880W6q+M+g= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=amd.com; Received: from PH7PR12MB5685.namprd12.prod.outlook.com (2603:10b6:510:13c::22) by DM6PR12MB4202.namprd12.prod.outlook.com (2603:10b6:5:219::22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9203.9; Mon, 13 Oct 2025 07:28:54 +0000 Received: from PH7PR12MB5685.namprd12.prod.outlook.com ([fe80::46fb:96f2:7667:7ca5]) by PH7PR12MB5685.namprd12.prod.outlook.com ([fe80::46fb:96f2:7667:7ca5%4]) with mapi id 15.20.9203.009; Mon, 13 Oct 2025 07:28:54 +0000 Message-ID: Date: Mon, 13 Oct 2025 09:28:46 +0200 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] drm/ttm: Add NULL check in ttm_resource_manager_usage To: "Lazar, Lijo" , "Zhang, Jesse(Jie)" , "amd-gfx@lists.freedesktop.org" , "dri-devel@lists.freedesktop.org" Cc: "Deucher, Alexander" , "Yang, Philip" References: <20251013015550.1317222-1-Jesse.Zhang@amd.com> Content-Language: en-US From: =?UTF-8?Q?Christian_K=C3=B6nig?= In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-ClientProxiedBy: BN9PR03CA0575.namprd03.prod.outlook.com (2603:10b6:408:10d::10) To PH7PR12MB5685.namprd12.prod.outlook.com (2603:10b6:510:13c::22) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PH7PR12MB5685:EE_|DM6PR12MB4202:EE_ X-MS-Office365-Filtering-Correlation-Id: 439c2182-4e09-4576-d18f-08de0a2a29a9 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|1800799024|366016|7053199007; X-Microsoft-Antispam-Message-Info: =?utf-8?B?M051cXAwUFpTaGpIZkdTdG1TUkNNaU1ZaVQ3ZWZxT3QvSXFwelVlKzdaSzNJ?= =?utf-8?B?dlZNbjE5VGc0OTQyOGkweXRjclZUSGRxeTdKdkZaQ2VNMDhJSXZJMHlodmNF?= =?utf-8?B?WCtKRTBMVDQrZ05oMURIenJLLzZFczBKYXF6bFZ1aEkzWWtJbzdZaGZTdXB1?= =?utf-8?B?SVZFanVCcGV3TjN0YjJabit4SVpTNHo5b1Q0WWpRdm1QbldWcGJjVThZNyt3?= =?utf-8?B?Y1prb2VqaVp3VEo5aGlzdllzZE5sRGZoeGpqdVBIQlZnUmdHbkFPdEVENmRE?= =?utf-8?B?SEp0Z1BWZWtJL3JsUkZScHFibFhuRzJZYVBOZEQvRXBIcTJOdVRSQmx0YUww?= =?utf-8?B?b0VBU0JWb0szOTZIRHR4OWpyN0FkWDlobCtpWit2Tm43dk9XUEh5M3czS3k5?= =?utf-8?B?bGJrd2k5TXZYT2t6RUxoYmJFMWFYdHJ1dXl4NjJ5Z0NlZVRFVzViSFp5alQ0?= =?utf-8?B?aHZkcENlZnNiSWFIWXB0Qy9reUh4em5hV3RtN0p3WW1MOStLcDY5VmZESUlC?= =?utf-8?B?WjMwL3AxdjcxQU9GRGlyRVlNZTVpYW1jL0pmZjFaclpiRjllV3ArS2hjU2Zm?= =?utf-8?B?N1Q5dWJLQ1ZJM0h1UXArS0ZzRmVTZ0p6TmVPaUVBNWVQalF0cS9wblV2eFBk?= =?utf-8?B?M1NQZjNXT3RTZ0J1MW50OWlNK05mVjEwS2xGeStxRHo5RzRKa0xlZHlOdHkr?= =?utf-8?B?aWtNSEtRaFA5Zlcvbm1VWVN3dFJ6ZTNFUVhvZFVua2NhcmlCRnV6ZFN1VS9l?= =?utf-8?B?czlTbmhuYU9KQUlJYWV1LzI5T0lGSU5QbmxZL0NBSUFiTXB5U01SNzg4Y2hV?= =?utf-8?B?SkJNY1VJVzhhaUxvOEdwWXBmRlBITlVIRm43ZE5MMnhsVjdHU1N3ckdLV1pz?= =?utf-8?B?NGFGUUNraFpiSG5xdVJXQ3oxWUxUREJMMWVoTE1lV1VKUlR5L2tQV3c2c3RK?= =?utf-8?B?K1B1Y0d6RU1kVDY5R1d3K2JoSjRTNjdhMDZwcHcrcEN1cFJmOTNKZnA3L0Y3?= =?utf-8?B?WXlPcHRIU3JlQ1JmMHB0bm9CSzhMOWlxRWRLTVFKMWpma3ZqUEh5ckxUdXFJ?= =?utf-8?B?SU9MRVoyU01ueTNUN1ZpbzA0Y2QwU2Rqb1Q0WkRCcGhrMERtL0Nnakozb2Y3?= =?utf-8?B?dHNsYXpkVTk0OVRTL0UzUk1YOFU1T1hRM3hweW9kL25hUVJIZGlReHF6M0h4?= =?utf-8?B?c3hadjhZSW5nSUMxU0F2eEhveVlMY0pUbDJMV2crZmRkajIzNGVCK0kyQUw2?= =?utf-8?B?MzBDKzU2NThtL25vT21CRDNPOW9abWdnMk85SWNiSVlvMk9PVmNSOXpKMUdV?= =?utf-8?B?QTE1NVEveTBsUEJWV1RjWVJjaGVSbFNYUGxUaDRYL2pxUlByYUZrSjI5NlNW?= =?utf-8?B?eENZZ25ZalEzMWpNMUVaYXF3andDanB5Z0JTcElnV3JCc3RsTWxTVjhCNFQy?= =?utf-8?B?QkRqWnBocmxsWHU0VnBoSFA5aGhwQXpiSE52Skp3cnNrRUhCMy9jZkFESDFa?= =?utf-8?B?RTNpY3ZEenZwOEU3L3ZtZGNrYStBbG80eU14dU0yczZlemJNVERMME1xd0or?= =?utf-8?B?QU1nbENyZ1F3Wi9NZXAzV0JJMmEyUld3UUptYmtMSExNNlEvbGpnbjRrV3d6?= =?utf-8?B?NExDMnkzWVdDZUg1WWJQSUd1ZElKSjBndWhuS1dFZ2c2NktuY3gzWThxeFdz?= =?utf-8?B?SU1YVENWakgzRzNCTVhSRW1XNFRMSkxTeFk4ODVYeTVCQkhtZ1NKTGhwWEU1?= =?utf-8?B?QmFqczRTTVhWc00wN0ZBRmk2eElXd0ZqTThiejR5M25kbmhEdzlRaFVzdnNB?= =?utf-8?B?M3hnV3BNdlZ6YzBjZ3ZBTFZlOW9UVTRnVkVTTXNucCs1SHdBdzNRT1JtN1JR?= =?utf-8?B?dUhJWldjaGtJSHV4TE9tZ2tjM3ZPU2R1dWVFVk5FejNheWZGUURNSzhkSGNu?= =?utf-8?Q?YyeyXbD7OSYo4kRqEAI14vCm4/aCPg6y?= X-Forefront-Antispam-Report: CIP:255.255.255.255; CTRY:; LANG:en; SCL:1; SRV:; IPV:NLI; SFV:NSPM; H:PH7PR12MB5685.namprd12.prod.outlook.com; PTR:; CAT:NONE; SFS:(13230040)(376014)(1800799024)(366016)(7053199007); DIR:OUT; SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?SjIycGRONkVhdWtnY0d2NG14M1RLTS9wVjByaTB0Ymp1QjgrN252THNxWi9r?= =?utf-8?B?RjRMb2pQSjI2L3hNQWJkS2Nqd3pWSDFFek9jYWs3NW8yOUpzRkM5SnlDL0NQ?= =?utf-8?B?eFhSQ00ya1ZvdzR3eWJndWp0QkhnbDFwVWJmdHo3eGFUMld5RU1tODZRTit1?= =?utf-8?B?bTdUM0loNE4vR1lDSlRFVHFDZzFNR0JhVzZMbk4wbkZPL0dMS0gvWVZ5RlpX?= =?utf-8?B?RXkzWHpHUERMWTVwM2wvenhWMjV1QlRRR3BQM01qVytLckIyVC93b01DMzVm?= =?utf-8?B?ZDhPVjR3ZDh0cVRmMjJMZldoeHJzazczeTE4N0NlRHF1b0NUVG5FWm0wMEdm?= =?utf-8?B?SUI0akp1MXZieC8yc1pLRTRNYlBBSEpDRE4xRDk1QzMwVkRPZDhQM2hYbTNz?= =?utf-8?B?OVkrOHdDMDdpM3p5OHRxV2w4cVpkSURjV0V0UU0wTlhqeVY4T0tySWcyM3U1?= =?utf-8?B?Rm9XRC8ycVRPbGlibDd5VVFRSWRhbFkyM1dEZ1ZrTVRGUjM0d3FvWkVvWk1T?= =?utf-8?B?SHRmMUEzWlAreFp4c0NacDhrdHFpUjQ2eDRuSkFjVWs2czVSUUxuSkcwVDRD?= =?utf-8?B?RFE1TWZrQ1U3Y0xRdmhJWEJIRG0vbUtxK0IwWlRkOGtRUEZramR1czRyV3dO?= =?utf-8?B?TTlaTjhUMjQvQng1ZDVYUDR1VGZjQmVRaGNyTS9VODkzdGpFMmlhL2JURzg1?= =?utf-8?B?d21vZ0NDbWFWNnNDOTRpU2VENkpoR2RGYjduQmhzemU2azFUK2NhQ1luQ3pm?= =?utf-8?B?ODAzVGVOdjBZT2duM3lpdVoyNnRMc0o2M21meEJHejRCbEkwWUk1emw3SlVl?= =?utf-8?B?QTBjK3AwUmFiMm1ISHVJQzRTM3d1MnJoY1JjRm12aENVV21BMXV6MVZDUkxx?= =?utf-8?B?dHhoUnR1YmJ3R0tuNWhFWnZWeEJOeGUycFcvNXJWTzZQZVFUUzJyTXBGM1g4?= =?utf-8?B?V2IrcENGeHgrWUZBQThYajQxZjBOMWs2Q1hRS01PUEtXY3hrTGV0ZllzYXBy?= =?utf-8?B?ZXlhd1pnRUI4ZlpPeWFoelVoako5bGJMNUhNeHZRa012dEpNcmIzd0V0QlJL?= =?utf-8?B?UDJUcVE4US8yOS9ZSVdnMHlrSUFDbnIrQ0tzRUlOREhtczFQcVFpU0k0T0w2?= =?utf-8?B?OVdMQmNCb2tWblp0NlNiUlJtL2JZYndUUWN5UzhKOGhjZXZZeDlQSzhvQ1dm?= =?utf-8?B?d0J1dElpNnJBL0dZWjU0N2NLV3QzMHVqMEdhMkdVekJmeURIQmFIT2oxVldI?= =?utf-8?B?Z1NOTGlpY2xuYXdqRUFZRFpSYTduYWl6cC9kcEVoRG1ycFk4L09VL1o2bVpJ?= =?utf-8?B?UXFyemJ1UGE4Zm1Wa0FsWlBSTmtEN1RJZXQyYityR3RqSExNZmlXNmQrSlpa?= =?utf-8?B?b09tRnl3eUVsL01uRGF4ak03UmJ3NjdLWnBjQ0ZpSWFGbk50dERBcHFyY2pL?= =?utf-8?B?a0NRNktWVjNKdlEvZ3JpRUJkelU0bGk3M2FJYmEySlc5UEE0YzlqdTNaMGVv?= =?utf-8?B?Nk85bDR1em9GOHo3dHRpbDRoQXJzY1lXQnIrZ3JDaTlTR0MvV2UxakVWb2RZ?= =?utf-8?B?V1lBTy9QdXhaS1V2R1Q2L1dmdk5tcklPK0xHT0liTjdWWThBMnY0VnVuZ094?= =?utf-8?B?SUgvSnV1TUE4eDE3RnNDeDJhOXg4N2xBa203N2ZUU0RqZmJSU2JrUU1YK05G?= =?utf-8?B?OUFITlo5VGp1UTFlcFExeWZUdzBxU1U0SnVDeDFacFNTR0UrZkUvTzJ1K1Jv?= =?utf-8?B?REhkcEUvUklIMVZZNVpOU21IN1J6aDZBTlZDWnFOOTVIWUxmS1J5bXkxQ29j?= =?utf-8?B?OFozcWw4amlxWWdJeWQ3M2NFbHVaMnRKSDRzcEl1blFMVE93RjBtZXpLaEVm?= =?utf-8?B?bGsxQ3hVMGR1V2JneThWTmJ4bUJpcU9xaWpUaml0ekMzT29CQW5Ya3R5UkVV?= =?utf-8?B?ejFLSEFoQU9uT2svVUtrUFJYTTZVeWJTUGZoTk0wNkppMENTb1Q4cnYyd3hU?= =?utf-8?B?ZkVpbVBQM0ZCVXF6OEpTcTJ6N3gyVU1JY01LM2Rod3RuSlRuYjB3NXc1aUJY?= =?utf-8?B?U1ViRUpFZG80VzhtUzdqMi85b0lRaVNmTkpmZUkrWnBEYkJueHJhWlVrSEo0?= =?utf-8?Q?1gIHQQPyM33D/Fya96Cpk0PYP?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 439c2182-4e09-4576-d18f-08de0a2a29a9 X-MS-Exchange-CrossTenant-AuthSource: PH7PR12MB5685.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 13 Oct 2025 07:28:53.9161 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: 310DasXqrM0REktX04QVXwjwKgyZ5fdxLjKLB8a7kyQmFd6N5F5opq8ouIOY5riT X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR12MB4202 X-BeenThere: amd-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussion list for AMD gfx List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: amd-gfx-bounces@lists.freedesktop.org Sender: "amd-gfx" On 13.10.25 09:09, Lazar, Lijo wrote: > [AMD Official Use Only - AMD Internal Distribution Only] > >> -----Original Message----- >> From: Zhang, Jesse(Jie) >> Sent: Monday, October 13, 2025 11:25 AM >> To: Lazar, Lijo ; amd-gfx@lists.freedesktop.org; dri- >> devel@lists.freedesktop.org >> Cc: Deucher, Alexander ; Koenig, Christian >> ; Yang, Philip >> Subject: RE: [PATCH] drm/ttm: Add NULL check in >> ttm_resource_manager_usage >> >> [AMD Official Use Only - AMD Internal Distribution Only] >> >>> -----Original Message----- >>> From: Lazar, Lijo >>> Sent: Monday, October 13, 2025 12:37 PM >>> To: Zhang, Jesse(Jie) ; >>> amd-gfx@lists.freedesktop.org; dri-devel@lists.freedesktop.org >>> Cc: Deucher, Alexander ; Koenig, Christian >>> ; Zhang, Jesse(Jie) ; >>> Yang, Philip ; Zhang, Jesse(Jie) >>> >>> Subject: RE: [PATCH] drm/ttm: Add NULL check in >>> ttm_resource_manager_usage >>> >>> [AMD Official Use Only - AMD Internal Distribution Only] >>> >>> The specific issue of trace with amdgpu_mem_info_vram_used_show should >>> be fixed with this one - "drm/amdgpu: hide VRAM sysfs attributes on >>> GPUs without VRAM" >> Thanks @Lazar, Lijo, maybe we still can use this patch to fix this crash when >> calling AMDGPU_CS and query AMDGPU_INFO_VRAM_USAGE. >> or add check like the previous patch. >> > [lijo] > > Agree, there are indeed multiple places of ttm_resource_manager_usage call. You may follow the same check as in the hide VRAM patch - ttm_resource_manager_used - in case ttm doesn't take this change. Yeah, agree. When the VRAM manager isn't initialized we shouldn't be calling any of its functions in the first place. Maybe it is a good idea to add something like "if (WARN_ON_ONCE(!man)) return 0;" to prevent the crashes and only get a nice warning into the system log. Regards, Christian. > > Thanks, > Lijo > >> Regards >> Jesse >> >> [ 911.954646] BUG: kernel NULL pointer dereference, address: >> 00000000000008f8 [ 911.962437] >> #PF: supervisor write access in kernel mode [ 912.007045] RIP: >> 0010:_raw_spin_lock+0x1e/0x40 [ 912.105151] >> amdttm_resource_manager_usage+0x1f/0x40 >> [amdttm] [ 912.111579] amdgpu_cs_parser_bos.isra.0+0x543/0x800 >> [amdgpu] >> >>> >>> Thanks, >>> Lijo >>>> -----Original Message----- >>>> From: amd-gfx On Behalf Of >>>> Jesse.Zhang >>>> Sent: Monday, October 13, 2025 7:25 AM >>>> To: amd-gfx@lists.freedesktop.org; dri-devel@lists.freedesktop.org >>>> Cc: Deucher, Alexander ; Koenig, Christian >>>> ; Zhang, Jesse(Jie) ; >>>> Yang, Philip ; Zhang, Jesse(Jie) >>>> >>>> Subject: [PATCH] drm/ttm: Add NULL check in >>>> ttm_resource_manager_usage >>>> >>>> Add a NULL pointer check in ttm_resource_manager_usage() to prevent >>>> kernel NULL pointer dereferences when the function is called with an >>>> uninitialized resource manager. >>>> >>>> This fixes a kernel OOPS observed on APU devices where the VRAM >>>> resource manager is not fully initialized, but various sysfs and >>>> debug interfaces still attempt to query VRAM usage statistics. >>>> >>>> The crash backtrace showed: >>>> BUG: kernel NULL pointer dereference, address: 00000000000008f8 >>>> Call Trace: >>>> amdttm_resource_manager_usage+0x1f/0x40 [amdttm] >>>> amdgpu_mem_info_vram_used_show+0x1e/0x40 [amdgpu] >>>> dev_attr_show+0x1d/0x40 >>>> kernfs_seq_show+0x27/0x30 >>>> >>>> By returning 0 for NULL managers, we allow callers to safely query >>>> usage information even when the underlying resource manager is not >>>> available, which is the expected behavior for devices without >>>> dedicated VRAM like >>> APUs. >>>> >>>> Suggested-by: Philip Yang >>>> Signed-off-by: Jesse Zhang >>>> --- >>>> drivers/gpu/drm/ttm/ttm_resource.c | 3 +++ >>>> 1 file changed, 3 insertions(+) >>>> >>>> diff --git a/drivers/gpu/drm/ttm/ttm_resource.c >>>> b/drivers/gpu/drm/ttm/ttm_resource.c >>>> index e2c82ad07eb4..e4d45f75e40a 100644 >>>> --- a/drivers/gpu/drm/ttm/ttm_resource.c >>>> +++ b/drivers/gpu/drm/ttm/ttm_resource.c >>>> @@ -587,6 +587,9 @@ uint64_t ttm_resource_manager_usage(struct >>>> ttm_resource_manager *man) { >>>> uint64_t usage; >>>> >>>> + if (!man) >>>> + return 0; >>>> + >>>> spin_lock(&man->bdev->lru_lock); >>>> usage = man->usage; >>>> spin_unlock(&man->bdev->lru_lock); >>>> -- >>>> 2.49.0 >>> >> >