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 153B8C79F9D for ; Mon, 5 Jan 2026 15:14:29 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 94D5910E434; Mon, 5 Jan 2026 15:14:28 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="cVTEcDFh"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.19]) by gabe.freedesktop.org (Postfix) with ESMTPS id 0A4DF10E430; Mon, 5 Jan 2026 15:14:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1767626067; x=1799162067; h=content-transfer-encoding:in-reply-to:references:subject: from:to:cc:date:message-id:mime-version; bh=MsoOWsxlDBhlMf/A/R8J9qbtV73XE7RECEagLB/zVG8=; b=cVTEcDFhqiOu0rwKwuZcyxD8PX39ao1iSAbAqPxqgI8XS8usuHwvScwW 7hbAe0L2dduVqq1WJHq81oYxWOawb8WrCFTdzVQbQY1M4MUoKZjKviGoe pCyNG7CeiEb98YBkv2GBfuYeLFrRZd23b5bTZKdsCkyJntDRlBNOvp94V xeg4O4lD9nemJPvqunTvUFEU9TsG3Mp10g2Be7XGV7YfMkyCpnRaW1ok6 tKv8zTLiCsIQPGHp8QW5S16dGSeLyFvpKhpaPxNiQbG+mCbSM2V/C8Szf mR8+ZfmETgOFBCEFi22xqRM8B+Q/BC6ifRFoaz1wNZOrek91OuJFj5WGY g==; X-CSE-ConnectionGUID: K3yRguBMSzW/WHwYyAww2A== X-CSE-MsgGUID: lxK0PbKvQEq1Lcqy2Z67Ow== X-IronPort-AV: E=McAfee;i="6800,10657,11662"; a="68897571" X-IronPort-AV: E=Sophos;i="6.21,203,1763452800"; d="scan'208";a="68897571" Received: from orviesa002.jf.intel.com ([10.64.159.142]) by orvoesa111.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Jan 2026 07:14:27 -0800 X-CSE-ConnectionGUID: +dqSx1ssRxGb/h5jzJrcDg== X-CSE-MsgGUID: 9uJ3Y5gxQTCsRuY5yAhDdA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,203,1763452800"; d="scan'208";a="233100953" Received: from orsmsx903.amr.corp.intel.com ([10.22.229.25]) by orviesa002.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Jan 2026 07:14:27 -0800 Received: from ORSMSX901.amr.corp.intel.com (10.22.229.23) 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; Mon, 5 Jan 2026 07:14:26 -0800 Received: from ORSEDG901.ED.cps.intel.com (10.7.248.11) 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 15.2.2562.29 via Frontend Transport; Mon, 5 Jan 2026 07:14:26 -0800 Received: from CY7PR03CU001.outbound.protection.outlook.com (40.93.198.3) by edgegateway.intel.com (134.134.137.111) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.29; Mon, 5 Jan 2026 07:14:26 -0800 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=Hc9cbCmLKahAC2D9QMtCDf51yg9SYfKU6kqs2VEH72yiER9TLbyg+wSyRA1Cyq5lzXdKHr18Y+lij9xCPvMgc0rACZGPEADWKKkTVj4WaIBmouQbo7O5UYmEu3E3Pet5ZP5VnQRjDBnLbtJve9DirkRU6gscjNvxpXTuxpQ/nBNPoipnJKuc5vu7H3Ej5U7/gpDATrTafy13M6lViqyPuFV1yY7WOFeGjCs8p4pFp8wGtxHmRO+OLKzqAcEegbZ36QaMWLiIiIBa8vZUFe+WtZuOLAhdCT6j1JxIiCx+vbQ+fK/F1uFHtPkUL+JgOYZ5rOEIEzLE63fzZDqyF+POPA== 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=/74dQCKjMeM80RDB1+e6y59KNVmMWb7dCqyuAShEWf0=; b=qQWhNJoOJ65KhrDPqx2cPmPqaEC/o+4LKaXGkXrCToQIm1DH/LsP1vskWJbKJqtYeHr/r4ACIBMT7P+Hr0pgn12HhMvjivRS0CwQM6d7wqSyfPnKvgI1qQiPH6M2qxOQW50MY7hISfMKQ4yA8ukmLbr074MwBB/U9s7YxKx2VCj9xYtumyA8B1DKUQ75nyCfsJ84h3rjkGGOOPNFE5V4oUI4qAYBdoT7W34Gul1LDnvB5PgOQY+6E/6Tm7IawFQSc6nLeyh+ksHhDQag+twE7xk0/RtDWCCA6DB1t+lf7bsLYQP8quCPapnTv3sVLY1f8d7copLqwh7ftb3L1gYAhw== 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 PH8PR11MB8287.namprd11.prod.outlook.com (2603:10b6:510:1c7::14) by SN7PR11MB7490.namprd11.prod.outlook.com (2603:10b6:806:346::22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9478.4; Mon, 5 Jan 2026 15:14:24 +0000 Received: from PH8PR11MB8287.namprd11.prod.outlook.com ([fe80::7e8b:2e5:8ce4:2350]) by PH8PR11MB8287.namprd11.prod.outlook.com ([fe80::7e8b:2e5:8ce4:2350%3]) with mapi id 15.20.9478.004; Mon, 5 Jan 2026 15:14:23 +0000 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable In-Reply-To: References: <20251230083142.70064-1-suraj.kandpal@intel.com> <20251230083142.70064-4-suraj.kandpal@intel.com> <176711619593.18661.17406989812251209808@intel.com> Subject: RE: [PATCH 3/3] drm/i915/cx0: Clear response ready & error bit From: Gustavo Sousa To: "Kandpal, Suraj" , "intel-gfx@lists.freedesktop.org" , "intel-xe@lists.freedesktop.org" CC: "Nautiyal, Ankit K" , "Kahola, Mika" , Jani Nikula Date: Mon, 5 Jan 2026 12:14:19 -0300 Message-ID: <176762605914.9480.7739153319106853404@intel.com> User-Agent: alot/0.12.dev22+g972188619 X-ClientProxiedBy: SJ0PR13CA0050.namprd13.prod.outlook.com (2603:10b6:a03:2c2::25) To PH8PR11MB8287.namprd11.prod.outlook.com (2603:10b6:510:1c7::14) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PH8PR11MB8287:EE_|SN7PR11MB7490:EE_ X-MS-Office365-Filtering-Correlation-Id: a35f2518-ec87-4284-8754-08de4c6d1bf2 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|1800799024|366016; X-Microsoft-Antispam-Message-Info: =?utf-8?B?UkxCVmFKZlIySjBrN1o2SWl1SVRobWtCTStnK01DeCs4ekZ6a2VjbnhyQ2hT?= =?utf-8?B?bTJ1TFRSQm40bmNFNnlVVUVkTzE2cHBrZldYWFFLWTBEMnhUR244TW51OWxh?= =?utf-8?B?M1Vkanl1WTRmUFdzNURZV08vM1pXNXZCcktzN055WTNqRWZ5clZudTlwZitk?= =?utf-8?B?eFBYQjNEOFJ6NGJmcnNaVlZnRDJHRUQ1QndFRnROQ3dtRFhDelEvYmVZcFJ5?= =?utf-8?B?SEFHMVFMUjJIcjVKWWc3eXYxVFBlc2ZwNTdnTVNORTVSL2U2OWVMWGNxTVJD?= =?utf-8?B?aktFWllqRFdadk1WekQ3elFEbG1xdnkrVGVEZHhhMWxET1VPUktUMjI1dUhE?= =?utf-8?B?MDlHSEdVZkpTTStmYWN3VjMya1cvRG5Gck1TSkxmYWhRUk91cm42UjhmMm5I?= =?utf-8?B?Mk51TkRCWE94S25uNVhEZTc1Y2d4N3BDckNjVTdHcmRlMUdtWXN4d2Q3STFy?= =?utf-8?B?eVRMWUtUcGpuc3c0RkNhRldYbDhiaWc4Yk1YWkJMWXlRYlpURUFXSmtURkhs?= =?utf-8?B?WUltL2V6ZExqdWNta091ZFFmTXQ2bkhRcjE5RXRBa1gyMVV4VWZLcVNTZVZ6?= =?utf-8?B?U0FDVDQ1Z1JXZ1hBYy83TGhEaE5OUTd1aHlxRTNvd0c4WG1mVzVEUE8yYy9R?= =?utf-8?B?Q2VBVmErbDZpY01nWVkrOVpOZ0UzbW96V0wwNU5iWmh5blcrekpKa25LOW03?= =?utf-8?B?cmd6UENDUEhZVWIzcnloQm8zUXpibU9Uc09FMDFzK3QySFVZSDFVV2UxbVpk?= =?utf-8?B?NUNKOXpxdWplMm5oV0s4NzhWMXBmQmhCU1RqSFNuN0VDVTlFQjYvakMwSGg0?= =?utf-8?B?R1U2b0RWVEtxWkpLMU02TmUxbWpBblN6RVJpK0xPQ0dkcGd1c0lYRE44WS8z?= =?utf-8?B?UXlZU3VoTXRJaEY5MTJxWVFERlQyeFNvSzlFMFV1Mk5JT2xRWHZKamo3dkpi?= =?utf-8?B?WDV3a2xGWWhndjg3K28zMmtpNnA4NHEzRER1U1lrS0hBNTByZTFlYnJtdUpM?= =?utf-8?B?Z3B0dUlWK3dWbVVNZXdNelJleVZyeFFsR1pqRTVGbFA1emRxaVRRcWlWRk9Z?= =?utf-8?B?VlhsbVBIWlJLbzluTERyaUVFMmZ2YUttZlhtVGd1Y2J1UU52dU1wdFdnSjVG?= =?utf-8?B?MmpnWVhhMEFPQU1WeEFNRzJBZnZCMWdjR2t4dXA1VUF2ZkpBZnVqZ3NjUDlB?= =?utf-8?B?QnhBdFJ3RVovd0pwN0s3RjVidFc4WGxnaVJ0b1djYy9aaXdBL21iUUlURG1h?= =?utf-8?B?cTh6TStzb3VramhKaGxWbkZGU3JQWmliZ054VGYyZy94MEJtcDJKdjl2U2Mv?= =?utf-8?B?TTJsRTh3WVEvL1NrN2NSS1lxWnVBREJYUEUzc1Y2TndYY1JIWjd1enlveVZR?= =?utf-8?B?ekFBT0NLZVY1K3RjdEpubjhlUy9EZnRFUHRzbEo0R2FkekZ3dTd4Sk93WWlB?= =?utf-8?B?TG5GTmppMmpJK1hXTkVKbHNSa2JRNjkwZlhvUmZDb3lLZmVJL0ZiRFFFNnhG?= =?utf-8?B?QngxK2NsdzlZbU5nSjRPSWtJYWh2VWlSY3hpcUYxV1plQ0FuUTZUd2VwMURG?= =?utf-8?B?STZBZFk1amUyY0lCYmRYNFc1dXpvbmphcUIzODR2ZGc2RTcySU9YUFNGdm5l?= =?utf-8?B?dnhsakM5VFVmTm9ydXczRDJIckNuNTA5VWZHU0RyZXRoZysvM20vRTAzNHNu?= =?utf-8?B?TnBUZ09jWXNiaVI1VzFnSldhNzZMR3hOMWFzNkhhT0VuVThEQXJWTWtnUHIz?= =?utf-8?B?WldFWDVsS01aUzdnN0kwQ3ZkUkkvWnRjLzJGTHhWZURNcWxhRy9DZTF6bVJZ?= =?utf-8?B?L0xBdUxYTFRPMHg4Z3VwOVdqR2k4WWc3ZkZLSW5ydVpKaWFGNHZicWQzWXZF?= =?utf-8?B?azVUeHJ0WndvUzZLdm85WnFUSU82VjdqNWIzaTRBWW45cjhOc29obGVDUExa?= =?utf-8?Q?6So4yrn6rwFcvEO2MBFD5DjRa2Ln82mI?= X-Forefront-Antispam-Report: CIP:255.255.255.255; CTRY:; LANG:en; SCL:1; SRV:; IPV:NLI; SFV:NSPM; H:PH8PR11MB8287.namprd11.prod.outlook.com; PTR:; CAT:NONE; SFS:(13230040)(376014)(1800799024)(366016); DIR:OUT; SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?cWttRE5PdnNYV3lEdFZCNXlzMXFsZ3p6RmtzNlFqcDh4NFY1R1lkaHdpSGZE?= =?utf-8?B?M2t4cUpoUU9OSTJTQjczSTQ2RFIzQzhKamVrWlByanc0eDErRTBhNHhGVllv?= =?utf-8?B?YytHZG9yeWdhR09FcTJTRG9UYXkzd0pHQ1I4eWlKUnJWaXFKWThDREpPbngw?= =?utf-8?B?dERCYXp6Z2tyQU51REhtOFJ6T0g1Q1MwcDlwdnROcE4rWnY5TWRyUm1NUjRI?= =?utf-8?B?TXV4S0V5Y0lGTWVwVlRUNmRDRWRiNTF5NDZqZXZMOU1kQVl2dnE3b0pnRC96?= =?utf-8?B?NVRmTUtKQ2J3Q05BYmpCM1dqNTFXZzcxVHBsRE1rWGNja1FQc0RHVy9sRlFZ?= =?utf-8?B?K3VXRkU4NzllMkl1c3hWbWk5Q1FidE5IekpaODZ0THk1c0pEd0tuTzFZYUV0?= =?utf-8?B?RU9qcjRNWnNBL1dnTHpNYWNWZEpOOWk1VEs0TWRVWWR1WndwRjg2L1EyMU5I?= =?utf-8?B?WVFITk1CQUE4OXBOdXN4YXF5RWw1d3BPa3gyU0lmandTNnBUVUdVNExRMm45?= =?utf-8?B?ZFp2aDJYQ0tYYnVwVzlHbFZFM0JhaEpVcXFJMWdCSE50ZXpQK3RmVlJFU3d0?= =?utf-8?B?VjdCblVRc0tBZmJYM1RhOGVmNlZLcksvaG9hS0tDQXlKTDk1YmtiRElPOUpv?= =?utf-8?B?NVJ0WXF0Q2tDVkdKcDgvcEc2dUN0eHhFenBuZzJLV3dNdS84QndzdFlqWWNS?= =?utf-8?B?ZlFhTytyajloakJhN0s3NndDYnUwQlpMOHA1Vy90QW1vVngyTkRDYmxqa3pO?= =?utf-8?B?OW1xNUtKSVNwYk5IWWY0YnRPQzFpajljbnRWbGRiVzhDYXdQbGRKNmtoWW1B?= =?utf-8?B?ZjJrekFHaUpaTVY3dHlBck9aQmdlZVZUNnhkTmNpSlZMWk02UnpYOFVzN1ps?= =?utf-8?B?YXdYY3NnOG1ubzBDOGUwVStHQ3NPTmxwbGN6YzB5REZELzA1MjJiNnYyTjVK?= =?utf-8?B?YXNyTDlrU2gwNEJVS2hBT0ZCWmJQeTNLOXJ2ZkwxcjR6c1pmeFpuQVJpY3kx?= =?utf-8?B?N3RUTFhUdFNaNFJhSXVsNnUxQzEyWFk4Q0xON2NJN0tiSnMyMmt3MXhCV3hv?= =?utf-8?B?QVJSb1hjVmJ5eFUzK3docFBtZUM4emxtZXhPbXB3YXdXZlNFTEVzUllrTnE0?= =?utf-8?B?SHBSaEs1TFpTdEFpU1ZsVndGempFNkpSOWUxWllDd2t2V1VxRHlseFh1K0l0?= =?utf-8?B?Q1VEV044NkhaMGdnTHVqY2lsOXVSSnM2cHI4aHRocGFQU3pNVmF2SlR1K0dW?= =?utf-8?B?TFIwaXhOMlBmRWt3NTRtZUNpQ0p3ZzlReExoQ0J3YWwyNXcwNGtDNHJIaHdW?= =?utf-8?B?bVkyUXhKbGFNY3FBQmhQY2phQ1pqTjdsSlp5b1phaEdEOWFNOXBsKzFkdith?= =?utf-8?B?Y0h0Vk1wWjR3OTE4Q0FXcUlQRWNvbVZoOFdhdzZsc1lxYzY5ZGtZKytlR0c0?= =?utf-8?B?NEoxQUVmS1FydVdZdjk3ekNIZTUwR1lwVTl3V0lLemp2clcvOFpQVThkYXgr?= =?utf-8?B?OXRGazA3UzRxWHdHdG9BNWlVMTVpcTd0Y21zMU5YMkdLRmhuM0pIRjg5ZHVi?= =?utf-8?B?ZkhOMXk5Q0VQOE5welBjZVNpeVNoZTFIREdSNVAyQ2M2eXpGZDNTWXZUYjFP?= =?utf-8?B?d0EzZU1xQXpoekFXS1lhUTdmY2x6NzR0dkJBaTBZazZCci9ZdVBXNmcyMEVv?= =?utf-8?B?Tk15N2tRbm1NanF1U1c2VFkvbVprNmNjUGtKK1ZSTnV5SnVvT2dxNCtBOUhR?= =?utf-8?B?L09yVTd6N0ZRUXUzMzQrMlJKZ0lUWkJ6aVI3eDQrdVowVXhGeGxIeWZvSEtS?= =?utf-8?B?dCswZzgvb3lQQm5oVHlOcjFrdlBGaXh1Qk1ZalozWDNaZzUvdW84Qnc2OXZD?= =?utf-8?B?NUZjblVORXh0c3IraVhPQ3N0K2JnVUNzRzF0YmZZMHlqTzhkalN3a2lYamU1?= =?utf-8?B?dVJIZ0FKNEdKd0piTExBZVJ1K01KWndtbU9CRnZ1VitvSFZ4ZVo3QXg5YlhT?= =?utf-8?B?bXE3VkR0amJwYnVIVnozbjdYL1NZNjU5V2R4YVlTYnk2UmZ1Q20reWh2V1BH?= =?utf-8?B?Z3dxMTBMR2g4ZzNDZUdvb0pHeFlZTXY5c2JTSkJrT1EycXBlY3lvRkZkamN0?= =?utf-8?B?QWoxdGhPTXBNMHQ2WmU2VFFhbzFXSjFmamhyanNhQXlIdzVhT1Q1TmIxY0NK?= =?utf-8?B?Q3Q4YW1SaEhSc3J1WlpXczlZYU1HWVlIRHBuZndpZzVHSHQvSXFsL1JuK3dn?= =?utf-8?B?STR0ZFllRWtYMzB2M0thUWF3SkZ2M0IzUDN6S0VOemRJZFN5bzNEQVJHVldP?= =?utf-8?B?L0lTSFhuVDdRdmREYUtqY1lrZ0E4d3dXL2pNQlFBK293VXloTG1TQT09?= X-MS-Exchange-CrossTenant-Network-Message-Id: a35f2518-ec87-4284-8754-08de4c6d1bf2 X-MS-Exchange-CrossTenant-AuthSource: PH8PR11MB8287.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 05 Jan 2026 15:14:23.8486 (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: VqnRnu+mYA296sOisCwbCULfde+AIqvT7GKD516gHu2rE/ud1g+eDXqJr3G9Y29l07ZYlSSqEnmYraXO/cs4uA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN7PR11MB7490 X-OriginatorOrg: intel.com X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Quoting Kandpal, Suraj (2025-12-31 01:59:29-03:00) >> Subject: Re: [PATCH 3/3] drm/i915/cx0: Clear response ready & error bit >>=20 >> Quoting Suraj Kandpal (2025-12-30 05:31:42-03:00) >> >Clear the response ready and error bit of PORT_P2M_MESSAGE_BUS_STATUS >> >before writing the transaction pending bit of PORT_M2P_MSGBUS_CTL as >> >that is a hard requirement. If not done we find that the PHY hangs >> >since it ends up in a weird state if left idle for more than 1 hour. >>=20 >> Since the series title refers to suspend/resume, is there an easy way of >> reproducing this via some power state transition? > >Sadly no we did try to no avail went as low as DC9 too. Tried sleep then w= ake, >Tried hibernating too. I see. I was wondering if DMC could be at play here. So the only known way of reproducing this is to leave it idle for more than 1 hour? Do you know if that happens if we load the driver with DC5/6 disabled (i.e. enable_dc=3D0)? > >>=20 >> I'm wondering if we are looking at a driver issue here or if this is rea= lly >> something else. I see that we usually call intel_cx0_bus_reset() in err= or paths, >> which contains a call to intel_clear_response_ready_flag(), but it could= end up >> being not called if the reset times out. > >Yes the reset times out and this is because PHY is in hanged state here > >>=20 >> Do we see error messages from the driver when the PHY hangs? > >Yes we do see a PHY hang when we are at the stage of swing programming set= ting >And the error happens when we try to read the msg access bit itself which = is because the PHY ends up in >Weird state where it has a write ack but no response ready bit getting set= . >But with my observation I can certainly say this is PHY issue. >I also double confirmed this behavior with windows folks and their code wh= ere they said they saw an issue in the same lines. >Also the bspec basically adds this as a disclaimer that response ready and= error bit should be cleared no matter what before writing >The transaction pending bit. Agreed on the need to clear the response ready bit before starting another transaction, so the patch looks fine. I believe Jani's request to rename the function wouldn't necessarily change the semantics of this patch, so Reviewed-by: Gustavo Sousa in case the rename gets done as a follow-up. > >Regards, >Suraj Kandpal > >>=20 >> -- >> Gustavo Sousa >>=20 >> > >> >Bspec: 65101 >> >Signed-off-by: Suraj Kandpal >> >--- >> > drivers/gpu/drm/i915/display/intel_cx0_phy.c | 4 ++++ >> > 1 file changed, 4 insertions(+) >> > >> >diff --git a/drivers/gpu/drm/i915/display/intel_cx0_phy.c >> >b/drivers/gpu/drm/i915/display/intel_cx0_phy.c >> >index 5edd293b533b..5ebc3404eee2 100644 >> >--- a/drivers/gpu/drm/i915/display/intel_cx0_phy.c >> >+++ b/drivers/gpu/drm/i915/display/intel_cx0_phy.c >> >@@ -222,6 +222,8 @@ static int __intel_cx0_read_once(struct intel_encod= er >> *encoder, >> > return -ETIMEDOUT; >> > } >> > >> >+ intel_clear_response_ready_flag(encoder, lane); >> >+ >> > intel_de_write(display, XELPDP_PORT_M2P_MSGBUS_CTL(display, po= rt, >> lane), >> > XELPDP_PORT_M2P_TRANSACTION_PENDING | >> > XELPDP_PORT_M2P_COMMAND_READ | @@ -293,6 +295,8 >> >@@ static int __intel_cx0_write_once(struct intel_encoder *encoder, >> > return -ETIMEDOUT; >> > } >> > >> >+ intel_clear_response_ready_flag(encoder, lane); >> >+ >> > intel_de_write(display, XELPDP_PORT_M2P_MSGBUS_CTL(display, po= rt, >> lane), >> > XELPDP_PORT_M2P_TRANSACTION_PENDING | >> > (committed ? >> XELPDP_PORT_M2P_COMMAND_WRITE_COMMITTED : >> >-- >> >2.34.1 >> >