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 644ABC5DF8C for ; Fri, 21 Aug 2026 23:40:39 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id DA81F10E2F4; Fri, 21 Aug 2026 23:40:38 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="jLcdanvh"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.15]) by gabe.freedesktop.org (Postfix) with ESMTPS id 7DEDF10E093; Fri, 21 Aug 2026 23:40:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1787355636; x=1818891636; h=date:from:to:cc:subject:message-id:references: in-reply-to:mime-version; bh=nWDfG7Qldq+guKpy/LdfoG7/00KZoDegXKxkOl8gQGo=; b=jLcdanvhx6oQidjfU8n3pYJXgAfb7nF2Isg6XAPeQiI4jJGfnhisU8XQ GUOdDsUsXx0MDLc5jAlVLvzKyrZYr9Zh0CSvZ8ktQ4jeZI4aE8MQ/IGmH phSDM6peMqrEFQaDIXcUjtkEevdBJ41oFh2b9MvgKH7Cc/jAtpTYIJLIn zDn8uvB8cYFwptJV2tg/NRm0ugLz5D44woc/rA8EcMaxvm9w6LOhogTo6 +HDsatd33T1ep9+9huf+eQEL9eFN9fIYPzckpU8CEWCtuFI4/b17FD8pA NZO4D2shfWnUeyKarfw9t/kM20mEmS634kYEy9Rk3+4x3fFHalPod3euq w==; X-CSE-ConnectionGUID: cW41tpfQS5SVMGLZCvdieg== X-CSE-MsgGUID: tSiAihu9QgSh6Hj5dTdeqA== X-IronPort-AV: E=McAfee;i="6800,10657,11882"; a="88036048" X-IronPort-AV: E=Sophos;i="6.25,236,1779174000"; d="scan'208";a="88036048" Received: from fmviesa003.fm.intel.com ([10.60.135.143]) by fmvoesa109.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Aug 2026 16:40:34 -0700 X-CSE-ConnectionGUID: f/F4kk+8QFivvXHCB+Cv+w== X-CSE-MsgGUID: sxrNkFs5TGCSreB7eVMWSw== X-ExtLoop1: 1 Received: from orsmsx901.amr.corp.intel.com ([10.22.229.23]) by fmviesa003.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Aug 2026 16:40:32 -0700 Received: from ORSMSX902.amr.corp.intel.com (10.22.229.24) by ORSMSX901.amr.corp.intel.com (10.22.229.23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.45; Fri, 21 Aug 2026 16:40:31 -0700 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 15.2.2562.45 via Frontend Transport; Fri, 21 Aug 2026 16:40:31 -0700 Received: from PH7PR06CU001.outbound.protection.outlook.com (52.101.201.29) 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 15.2.2562.45; Fri, 21 Aug 2026 16:40:29 -0700 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=GrL27y4xbWKQJz4aMK0dWBUjDvcJbBlD2cpxUp9MF6lSmtW/ptyAETYVhPU6gQXEpawSri/55itQZE6XPxYdgloky9oAX61bbFh/B1O+8ewqxz83JcZZuEPv8BJuryHIpdhghxJWcU0DRh1Jc/X3qoPaLCs1HJ/x/kcwo5etwPHfYhQ6UGlhYSh8LcVmDzhr6mlxl2stAw5u2JlyUrq+tZ9+xj5MYpgq3lgBTUe7eH8tfaM/pRl6AZiiIbR5Hg3RaFN8Q5lrGg6ZrEINAeJekMMaD9k3adPs+1HIvxOzu1z5LvY3Fhlvrbb59yGdeBLzGCxV9m+QIK4UghgLH/DVZg== 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=9H8WltDPiBcvyYASRzdKpMs2u/NLOoB5ywlwTeN2ldw=; b=vQAB/0ssWEdL+CDC1A0xbajyt0Cakv9+/ZyZqiyIuctViEUEE1E5F4RTuWYSxTM4HvLNsNcNM9LH37S9fk+Sb1+4Xin3JQ4spkd9b8gghBXyTW2yiPT0kZV0IWTwsXSVQdDgNNpkb8LIf7j8Ju22PgVJSNzRPGzjBdCMwZp9ZhhEe83NgJW1Kjw8FV64HUJikRtVW2hsMiCWTwGkjh+IAQcnRN3ql73kf+qSyqoTFILYOU3UNyGdPvD6H1wNoOpGCLlljC2IW1FScwdVobpPdlIb2GMtEs+g15nzBrK4T8oi17exbkchjsWLOKeNqwrnh48GO2zZUZ9SRE1Kx3YzWQ== 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 BL3PR11MB6508.namprd11.prod.outlook.com (2603:10b6:208:38f::5) by CHAPR11MB9630.namprd11.prod.outlook.com (2603:10b6:610:301::11) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.339.11; Fri, 21 Aug 2026 23:40:25 +0000 Received: from BL3PR11MB6508.namprd11.prod.outlook.com ([fe80::53c9:f6c2:ffa5:3cb5]) by BL3PR11MB6508.namprd11.prod.outlook.com ([fe80::53c9:f6c2:ffa5:3cb5%7]) with mapi id 15.21.0339.010; Fri, 21 Aug 2026 23:40:25 +0000 Date: Fri, 21 Aug 2026 16:40:21 -0700 From: Matthew Brost To: Linus Torvalds CC: Matthew Auld , Himal Prasad Ghimiray , Lucas De Marchi , Maarten Lankhorst , Rodrigo Vivi , Thomas =?iso-8859-1?Q?Hellstr=F6m?= , "David Airlie" , Simona Vetter , , dri-devel Subject: Re: drm: xe: Kernel-submitted job timed out Message-ID: References: <6874536d-ab1a-4dd7-a23f-2a071bda145e@lankhorst.se> Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: SJ0PR03CA0331.namprd03.prod.outlook.com (2603:10b6:a03:39c::6) To BL3PR11MB6508.namprd11.prod.outlook.com (2603:10b6:208:38f::5) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BL3PR11MB6508:EE_|CHAPR11MB9630:EE_ X-MS-Office365-Filtering-Correlation-Id: 38315aab-ab99-46a9-d7fd-08deffdd932a X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; ARA:13230040|366016|23010399003|376014|1800799024|10067099003|56012099006|4143699003|11063799006|18002099003|22082099003; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255; CTRY:; LANG:en; SCL:1; SRV:; IPV:NLI; SFV:NSPM; H:BL3PR11MB6508.namprd11.prod.outlook.com; PTR:; CAT:NONE; SFS:(13230040)(366016)(23010399003)(376014)(1800799024)(10067099003)(56012099006)(4143699003)(11063799006)(18002099003)(22082099003); DIR:OUT; SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?82T+R9WHGfo3kkH4qCnHK08ex6RSK5JDeblfM11lSaQf7LR0xlIPleLBj0i7?= =?us-ascii?Q?OWeYRmAz62gWaE1EanqzXeREx9Yua8mx1r++RBtxVzjasQOTiWNZtZP2lsEx?= =?us-ascii?Q?P9dUGqf30zZziRsp8Cs322IXgC7mABSAhaZ+Ptyf0Lg8oq9Z1SyILkLxxXdC?= =?us-ascii?Q?4RHBjP+aEm8g3e5jqWQK8te+2+n2bQn3v7ybhhit11i4G0waiioBV+f0jRtN?= =?us-ascii?Q?kzPzJQuU19KyDGwkhDrulgIgEl5de1HIGUtyEOZuUgvwND2AQA3lD6Fsdkr8?= =?us-ascii?Q?4hkFWof/AUwTA+PPBCFqJWdOaWLrtr6Flqv9ME7ryIcX7rGRNK7Bae50XqMZ?= =?us-ascii?Q?y3S300VTQ4Yr5ldFySWVSeGuQWsu8i+bezx1LwLPaWX79THr+tt1R961S4Cy?= =?us-ascii?Q?hz2jq27SPis5i77V4L27+OskzS1rQnR7zmkv3EPqvY0TD8N+M1AejzRs4TYI?= =?us-ascii?Q?kk7ouVd/8kCS8T2VjXABFM9Up+hWRbpB6jze3s4i6AkEuXAP7IWKemWegYvM?= =?us-ascii?Q?FzFenY1cqCF0Mem3d8XlXvTGEVOVNzjUOG9XeAGVZfjjUVa71XhtpBh+k2k1?= =?us-ascii?Q?M1jl7yUlQb87UFTVTflZgnUfVoMqbhQPDJ1Giex63CiKmtAQqVuX712wBLYI?= =?us-ascii?Q?yq0/yNYy/uEVU4pUd4+d0Th1xz76rHMyLdfVV/M3fdqRlxsoajf6UAneeE2H?= =?us-ascii?Q?aUqbd/tTP/BO8Xtn353eedBU6m4Z5iJgGQL5iMZ9TT1+ZdGBEQbXPPAq48yu?= =?us-ascii?Q?UNPz+7fC+eDt3xyWhTXas/+fDw8Tq/gu30sZyAUju4lZDhTT0IOk09xrZE6Q?= =?us-ascii?Q?NAPLAKVw95pA4Iv17r10E7+auzTIjXeWZnKMzwLAkswycDT4ckNBz6gBUfHy?= =?us-ascii?Q?AYh7wQEusXxJGjkhlfzlbbKt/ynDX/FNQRhHwyyQpWtU2dwuZlpYnUCraLun?= =?us-ascii?Q?Ns9JnIUtPDUfjVhPNnHYfcSEFDset+L6RDAHwI2xWeQtmzCs9B3rc8JYO3gG?= =?us-ascii?Q?LHBUXkGSd712APQrQ1i+cpP1KxpXgXbtr7T0IUJHpx4RTAxuSrokt8IUBqzw?= =?us-ascii?Q?Dlm3BsbOOPmVKdcNqf/3/DFqt2vw9NgRkCQtTg3nzy2XF6GO9tRExaZpjREK?= =?us-ascii?Q?MUDsBcwn/mqR5BACZM1jVecXr1L/Put68YV8GCLG9WV5E5ubMc1XcStBYI4d?= =?us-ascii?Q?4yYrHp1n0qL/PpB339aI84yotRGwhymgh1Nu4gtbdJzahBF98r6BAonEvW9I?= =?us-ascii?Q?McnyIQQkqdV1ZCvE+nlIbllneBqVseBYDWsLYGJO/IVE4S3RPgVR7g/T/Gc+?= =?us-ascii?Q?f5ngmWBNPmUGoxjpfRklaOoWFAJBGg0ESgkhRuSHz1AVYqEilrSIQ7UnXKiK?= =?us-ascii?Q?T7fPBcDhiNHTxdsfZ8BOxGUuZM7G8P1id/p0p7cM1aL65owce2pJGqYfy0hn?= =?us-ascii?Q?iVi2dbrguK2mYurI/flOtqQtN9i/7c0cLKlAYHEAvQH5ko0CXPkY5XvoiPwC?= =?us-ascii?Q?bYbzGS1sjNCTjdptwlHSs3UhveNzoRLl8TCnIxLrwjr2buNwm75myNwXo7M0?= =?us-ascii?Q?uY47kGZwSOqzxLYavsuUzU/p0KOdvS6Rk2u90WG2KHC/jVRUR44hJLQBuFF8?= =?us-ascii?Q?GItiyO+KxNG+0aScSR2tPYpYhh7LkLWZY0GY+NJPm/kj23DXbnpPn8ddFPqc?= =?us-ascii?Q?B5yi5jcrnqclqzAJqpkr0E+3Ra+dtQePZZxmAjB0n1lIDquJUFlSvg6W81Ya?= =?us-ascii?Q?nl0KVgu91xlrbtsJY/heYVL+1nZqW5I=3D?= X-Exchange-RoutingPolicyChecked: iJOmag1eBvcr0yYG9P8/4NoTYt8QSQbtcoeVVqmoG/RSGP3edVPctDRMywD4c88O0rB8251F4rnftTesbj4khEU54P61ugIHFZ9cI2bII/MNmdbOWcZQYzvqsYIEH/wzLr7fbMU61CklpG0mBApMEJSePL69w+mTRnWR66+hb3HpiDKqZILSBWkbiQjJYahpDxFMSMJBZwUpp7VIPA2RtWWqaF56c/RTuw0sMrMPh00A+S8TLFvh8TlfnT1pf4YFtUp7IbywpbgCfh11J9Mt9UGbee8vgmrRysWZcZRW34rF3YkhdGftS4AaoIxsivHiIvy7BjqmLJhv9hiv5tvGbw== X-MS-Exchange-CrossTenant-Network-Message-Id: 38315aab-ab99-46a9-d7fd-08deffdd932a X-MS-Exchange-CrossTenant-AuthSource: BL3PR11MB6508.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 21 Aug 2026 23:40:25.8314 (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: AXCv8z41h58RBsh73zEy6H2cgfR/sudhbKCDEPVZEuoSjh0yXZ8iVMFaKZZCtVowxZqOmxYucdlW5B1gyTxI6g== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CHAPR11MB9630 X-OriginatorOrg: intel.com X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" On Fri, Aug 21, 2026 at 09:47:53AM -0700, Linus Torvalds wrote: > On Thu, 20 Aug 2026 at 20:50, Linus Torvalds > wrote: > > First, thanks for looking into this, and I apologize for the inconvenience. I had gotten to the point where, based on my testing, I had reasoned that there was memory corruption somewhere in Xe that was writing garbage into the page tables, but without a reproducer I couldn't determine exactly where it was occurring. > > I committed the fix as commit 818bebeb63dd ("drm/xe: Don't hand out > > the flat CCS storage as usable VRAM"). > > Note: that is most definitely a real fix, but it's not necessarily the > *right* fix. > > For example, I do not understand the old 128kB alignment at all. It > not only was definitely the wrong way around, but it made no sense in > the first place. > > The comment for it said "SW must round up to nearest 128K" and the > original broken commit seems to imply that thatt comes from some > hardware document. > > But the result isn't actually *used* for any hardware state, as far as > I can tell. It's just used for "vram_size" (called "usable_size" in > xe_vram_probe, which as far as I could tell is only used by the driver > for the allocator. > > So the whole thing was just complete garbage, and I don't understand Yes, this is garbage and can corrupt memory. > *why*. I may be missing something, but yesterday I was so fed up with > the experience of spending 10+ hours debugging what ended up being a > one-liner that I just committed it as-is. > one-liners tend to be hardest ones to find, again thanks, apologize, etc... > Now I'm back after a night's sleep, bright-eyed and bushy-tailed, and > still not really wanting to look at it, but at least wanting to tie > down some loose ends. > > So I just want somebody who actually knows the Xe driver to look at > that thing. I only round down by 4k, not 128k. I think the 128k was > simply wrong and nonsensical. But that number came from *somewhere*. > > I claim that the old 128kB number cannot be sane for another reason: > the other side of that > > if (GRAPHICS_VER(xe) >= 20) { > > will return an offset that is at a 64k granularity, because that's > apparently the hardware field definition. > > But the point is that the return value of get_flat_ccs_offset() > clearly is *not* 128kB-aligned and never was, so not only was the > alignment done in the wrong direction, it was always entirely > nonsensical. It cannot possibly be something that the allocator code > then depends on. > > Anyway. It all now works for me, and apparently reliably. But the > keyword is "for me". I committed that thing because the old code was > clearly garbage, and the new code worked. > > But the new code may be garbage too - for some reason that I simply It will pop an assert somewhere else in the code, but that is also questionable. > don't know about - so somebody competent needs to look at it. > We are looking into this now and get a proper backportable fix post asap. Matt > Linus