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 56868FD461C for ; Thu, 26 Feb 2026 04:55:34 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 17FAD10E109; Thu, 26 Feb 2026 04:55:34 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="L/WkkDAh"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.12]) by gabe.freedesktop.org (Postfix) with ESMTPS id 9E41910E109; Thu, 26 Feb 2026 04:55:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1772081733; x=1803617733; h=message-id:date:subject:to:references:from:in-reply-to: content-transfer-encoding:mime-version; bh=JYvCZfETEOLOUNal4vwnxIz8ekUDG4tNWmHPxYhVGB0=; b=L/WkkDAhDhmSG51xyc8rmdn70g05RuiU/K4Keaur4lKJbB+a3nrVd4OU 44gFOLh0y3yC62w6IqjP2KlC8Gx1gk8kJczO4toPnWP3b6vnM0NuZNGo7 GvT+XFvFOL2NRcGrTkcE14mxEbRZmwPUO6vwvL/1aKi7pGJJW8A+RS8nk 1R3WM057eOXfoFCI9UPm8WZKl9ewaZkv8dg/BhAIHxkm0QDitpObTit0O DMl4Sz6z31SW/G379RLgiKu7y2JYnFZLJ+dPJq0jWr5gaRlEd1QZBsFa9 HVz7j/JibnlnehJv6UdAe1bGaEvq8xKxHH4LytA1t7A6TcCx0PFhDr3w8 Q==; X-CSE-ConnectionGUID: 4i2DIDUwSSCxF16YDSKpRw== X-CSE-MsgGUID: 4i2Gi9I3STyRIFunYoaZ3A== X-IronPort-AV: E=McAfee;i="6800,10657,11712"; a="84590811" X-IronPort-AV: E=Sophos;i="6.21,311,1763452800"; d="scan'208";a="84590811" Received: from fmviesa001.fm.intel.com ([10.60.135.141]) by orvoesa104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Feb 2026 20:55:32 -0800 X-CSE-ConnectionGUID: 72qotR3YTU2PLejyINxbBg== X-CSE-MsgGUID: 5u8FKqq7STWKJohC+xJdKQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,311,1763452800"; d="scan'208";a="244093014" Received: from orsmsx903.amr.corp.intel.com ([10.22.229.25]) by fmviesa001.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Feb 2026 20:55:32 -0800 Received: from ORSMSX903.amr.corp.intel.com (10.22.229.25) 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 15.2.2562.35; Wed, 25 Feb 2026 20:55:31 -0800 Received: from ORSEDG901.ED.cps.intel.com (10.7.248.11) 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 15.2.2562.35 via Frontend Transport; Wed, 25 Feb 2026 20:55:31 -0800 Received: from SJ2PR03CU001.outbound.protection.outlook.com (52.101.43.37) 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 15.2.2562.35; Wed, 25 Feb 2026 20:55:31 -0800 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=dwicTIhMg2FthWcNiy7VgYo+CJaKvZwng/q0ZKfxFhooBGvhaldf4VmgLdCOpDr5S8XKNhNJWqIQ8AEUKsiDDU77PYCcDidyA2M/EbwtTnTV+deQ0VZD/XjOc/jX6njh9OqW8UIOfop1ya26Lx+uO26uVTuJ3gwR/1vuW76/cDsAWB76JUXn65y3W431OOxiECWDHM0fIHRAETWW/7bu+uWfcE9cXhj5lUMLjpX3eTKvr3EDhTen94f8M00iab8mBaswEVW6oyghzKfRrbpzakrOT5wKgGODrTL+wDod1jaO5O/N0O4f1Nc+WTcYs6vpNXDEG/PiNHnHDY53cSmkSA== 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=NrVSPCWVF5mKlFtmo9aNTs0kGMs++ZNrw6nOGIl50XQ=; b=ubB1qVuR2IHmW/oHFcXaMFFocV6fXivYpoHRUfj2WiRfvPhK8Sk4z/Czg+oI2kki+Nl4MzBhInLK/2MLX8y3WBBygPNJGBVXisDiDA+aMecOQmnv8iusKYeYxYBhBleBShkq+DbPNkzTONYfyeWsDWBCFhI8TrTw48E4xu0jgvds9emwVBqet4LhvpFldt8ozygoxFQRoYrKAeo4wJe9zRxVQ74FXPsANOYmI9Ulww10cj93pwS4bJpYUikpS8hanncuoYiwhnJVyU4+qImu7v1ZHXYu0wxPg1Afg45ntgRe7xqKGgP3VLbRZdRTgNXNln68obhPNBSIkpB+UFfe1g== 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 DM4PR11MB5341.namprd11.prod.outlook.com (2603:10b6:5:390::22) by DM6PR11MB4564.namprd11.prod.outlook.com (2603:10b6:5:2a0::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9632.21; Thu, 26 Feb 2026 04:55:22 +0000 Received: from DM4PR11MB5341.namprd11.prod.outlook.com ([fe80::68b9:ea3c:8166:3cc4]) by DM4PR11MB5341.namprd11.prod.outlook.com ([fe80::68b9:ea3c:8166:3cc4%4]) with mapi id 15.20.9632.017; Thu, 26 Feb 2026 04:55:22 +0000 Message-ID: Date: Thu, 26 Feb 2026 10:25:16 +0530 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] drm/i915/backlight: Remove try_vesa_interface To: Suraj Kandpal , , References: <20260224031322.2568874-1-suraj.kandpal@intel.com> Content-Language: en-US From: "Nautiyal, Ankit K" In-Reply-To: <20260224031322.2568874-1-suraj.kandpal@intel.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: MA5P287CA0280.INDP287.PROD.OUTLOOK.COM (2603:1096:a01:1f2::18) To DM4PR11MB5341.namprd11.prod.outlook.com (2603:10b6:5:390::22) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DM4PR11MB5341:EE_|DM6PR11MB4564:EE_ X-MS-Office365-Filtering-Correlation-Id: a2a2a0c7-557f-4756-5192-08de74f33f7c X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|366016|1800799024; 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:DM4PR11MB5341.namprd11.prod.outlook.com; PTR:; CAT:NONE; SFS:(13230040)(376014)(366016)(1800799024); DIR:OUT; SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?WG5aWlRoTmJscG5WNlcrWTNoSXV5b3VGMXB3YTk1cit5MkxaamJJWU9BZkpw?= =?utf-8?B?SktvOHVONFpSVlpsS2F5QzlzNHNqa3ZpRGJkZDdYQUJPTHR0UDVXZDBJRmxi?= =?utf-8?B?MFZGTUhtS2lsNU5xUUhZUElmcTlaeEJmNnlJLzBxUTFPNUZPYm92d1o5Mis2?= =?utf-8?B?TWo4c2h1Ykd5VGJKNnlQSDhKKy9acCtFM0xEdkUrM2xabGc2YUsxSEpwOG1R?= =?utf-8?B?S2FFc1p1SFdzSnBYVmM0dDlSVi9hM2c2TkZBSGc3YWhYcEliVDhBaitVS2xQ?= =?utf-8?B?UFVRYy9XamtKUHF5WFBtMlFqWHBIMVozMkpTMmhlUDBhbnV1dGVnUlh0OGNo?= =?utf-8?B?Znhxa29FRFVjYmUxZVBLR0dVRm1tZEEvU1R0QTBSaGZ1S0Y4MS95NWFKOENy?= =?utf-8?B?MXJRVWk1T1Y1Y2tway9iU0VETS9EV1JjVHIvQ2FhVjRoS1BqVGU2UFlaNmUv?= =?utf-8?B?U05qRWM1Mk5UVlVlN2dTZDV0SGRSNi9UbGEvei9kaGZJQkRaZFcwMXk1eGNV?= =?utf-8?B?MUhmNlFjcEJKY3U2cHRDS1ZpQndaWkMxN0ZMZXh4M3RXMVI4V3BBdUV0V3lD?= =?utf-8?B?MXdtTFlBQlF3U2srMDFpM1NKQlRqaGk3bHM2Z1VlOWhEZUVhQXR5NVdURDlR?= =?utf-8?B?OWloakRsNlRJQVpDWUJtZUp1ZWEzQ3dzeGFHSm1ZbThZdTZPNytYNmJ2Y0Y4?= =?utf-8?B?UE9yOFRuRDJxV2JjTDMxZjNWcWlBUkQ1NDNyUWlCMzFmV25ReHZaa2FiTFht?= =?utf-8?B?MUVLR1poWFVuOGc4MDdZZ1g4aUtjc3pkTmluL0gxeXQrcFRZT2xWL0MwR2dU?= =?utf-8?B?SXZtbTh4eEI2aXhvcy80NVJjaEFYcGFqV2thY1E5MUtpUFRGRTJReXgvUWtQ?= =?utf-8?B?UU14Y2Vlbmg5UklnMTZNVk9HVE9ZRlF4N1BRYm5nR0c5K1ZYY05DNi9tVyt1?= =?utf-8?B?SkVQbnJFSjJCcjRMZCtUcnN4ckR3KzJZWDZtSVBNY0hkZjhQMytXV2RPT2cr?= =?utf-8?B?bmRUdzRvNndQK1ZneHJHbmd5Q09ocFhCcGd5anZrbHlJVUtXQ2NqRDloYnBK?= =?utf-8?B?bDVESmQ3WW90U2V4M29DR2Z4TXBpU3RZUklLNHNyajRCNFJ0OWtrck5OYXlJ?= =?utf-8?B?OU9YYzU2dFFMeGJ5aHZXbzJMTDZheDlPYVFQSjV6bTZVc093Z1pLNmEydVRV?= =?utf-8?B?M0NBU3NCMWV0TjJ2bUJwbXNpWTkvdUtkT3dhVVRwR0lCQng1MTIvWVpYQWox?= =?utf-8?B?a2hQOFZZQVhZditrY2FiUWtBSnVWNGFZMG9FRWdKL0FRT25IVUVEL3hpRktR?= =?utf-8?B?cU5yUmlYVFlleG1rRmhudFVINDZXY2trcmF5ZFVyeFF5NDYra2tuKys2cnpL?= =?utf-8?B?M28yd1Y1bndiU2FXTmw2a3RIamErYmtmVmkrZ0dWbnJJa3lvd080aVgxbGxi?= =?utf-8?B?ajc2SS9jOG9tVytrc1BubTBuQmI1UHByaGVjUVJnSTFSWnNPQVdnMHNKeW5X?= =?utf-8?B?NFEyYkhhOVcva2RNK1FKVFBwdzBYK3JIYkVxaS85c0tOd00rRUZNOTc2VTR4?= =?utf-8?B?eEtYaldmejRGMkpwSkxHWWMvU1ErSEVVWSsveXNxbDhQYnlwTldtWDR2cm0r?= =?utf-8?B?L2NqYlkwandGaHEvVVNCQk1JbjRLV0dodlJWY3d0Rk0xaFpUaVcrN3pZZ0sw?= =?utf-8?B?VFVxR01uTVNtVGs2aCtTU1ZldU9qMm9VZnh2RmIvYXE0N3NjZVR3clJFNndi?= =?utf-8?B?dWZqM2owd3RlTy9lbnRkYUNCSStadG1KcW1CaXJFOFZiMStCdmNZSGtvZ2dM?= =?utf-8?B?Rk5Od2ZNalNtZisvcDBPbDFOMlhTZkVwckpGanhBS3hsZDBmSkFwem1zd0l2?= =?utf-8?B?TGlLcXRSbW1QY1Q2aGJNYUc1bFNYTlIzNWdnSnhUYmxZcjlOYmcrVTlCNGx2?= =?utf-8?B?Y1dwMnBaSVlrTFVnbjJ4Q2JMcVVpWWkxVUpYeEl2REdFMGhzazZPbngwQU1s?= =?utf-8?B?MEpLNjY3WkNrNEJJQko3R1VPbFU3M3ZLNjRic3VDOWpOaFJwblpUNEllNDh6?= =?utf-8?B?MWVOS2tTcFJyVkg0d2tYMWtWNUMrR3FCcE5YMCtOVTJLRHdRd2hhWUsza0Yx?= =?utf-8?B?bUlQb1VEdkU5eGYvMytrcWxBU0hJV3hlVTF4WWV2em1zTm85c3BBVW9JWmFH?= =?utf-8?B?M1QwS1oxd0RNSW1VWGRVR2w4czRhU0FnMXpZL2JvaXdFejhHTnNsU01pQXVq?= =?utf-8?B?SWJkcFpUYVhUeGd1REd0NG9KRFZIVUNZd3BSdWl4UlFGbkIyNVdVdEtVbHMy?= =?utf-8?B?Q1dQNEFNTkt3Z0ZLV0hoQWRIakxlRUtrK0RBUmwzYjIvbFk4SXhXaVdQN3Y1?= =?utf-8?Q?5OFT1mcx8dYAuabw=3D?= X-MS-Exchange-CrossTenant-Network-Message-Id: a2a2a0c7-557f-4756-5192-08de74f33f7c X-MS-Exchange-CrossTenant-AuthSource: DM4PR11MB5341.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 26 Feb 2026 04:55:22.7363 (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: 3DeRaq8lALr35H0GHMyQU6CdkqitJC7Cww2XyrEREAKtgNPCfbn7TucavnEp78/KBo/CA7SQ7BEu4RfpOTHFkAw1oQ3sXu6Nz31crNVQn2A= X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR11MB4564 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 2/24/2026 8:43 AM, Suraj Kandpal wrote: > Remove try_vesa_interface. This is because we now make VESA Interface > as a fallback mechanism for Panels which needs VESA DPCD AUX backlight > mechanism to work but have a broken VBT indicating otherwise. I think lets start with the problem: - some panels need VESA DPCD Aux backlight but VBT says otherwise - we try with Intel backlight interface first, then check for try_vesa_interface flag before trying VESA backlight interface -this causes blankout on such panels as try_vesa_interface is not set and VESA backlight is not tried. - remove try_vesa_interface flag and lets attempt VESA backlight interface as a fallback mechansim. > While at in sneak in a small comment cleanup too. > > Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/15679 > Signed-off-by: Suraj Kandpal > --- > .../drm/i915/display/intel_dp_aux_backlight.c | 19 +++++++------------ > 1 file changed, 7 insertions(+), 12 deletions(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c > index eb05ef4bd9f6..a8e9872566cd 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c > +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c > @@ -644,9 +644,10 @@ int intel_dp_aux_init_backlight_funcs(struct intel_connector *connector) > struct intel_dp *intel_dp = intel_attached_dp(connector); > struct drm_device *dev = connector->base.dev; > struct intel_panel *panel = &connector->panel; > - bool try_intel_interface = false, try_vesa_interface = false; > + bool try_intel_interface = false; > > - /* Check the VBT and user's module parameters to figure out which > + /* > + * Check the VBT and user's module parameters to figure out which > * interfaces to probe > */ > switch (display->params.enable_dpcd_backlight) { > @@ -655,7 +656,6 @@ int intel_dp_aux_init_backlight_funcs(struct intel_connector *connector) > case INTEL_DP_AUX_BACKLIGHT_AUTO: > switch (panel->vbt.backlight.type) { > case INTEL_BACKLIGHT_VESA_EDP_AUX_INTERFACE: > - try_vesa_interface = true; > break; > case INTEL_BACKLIGHT_DISPLAY_DDI: > try_intel_interface = true; > @@ -668,20 +668,12 @@ int intel_dp_aux_init_backlight_funcs(struct intel_connector *connector) > if (panel->vbt.backlight.type != INTEL_BACKLIGHT_VESA_EDP_AUX_INTERFACE) > try_intel_interface = true; > > - try_vesa_interface = true; > - break; > - case INTEL_DP_AUX_BACKLIGHT_FORCE_VESA: > - try_vesa_interface = true; > break; > case INTEL_DP_AUX_BACKLIGHT_FORCE_INTEL: > try_intel_interface = true; > break; > } > > - /* For eDP 1.5 and above we are supposed to use VESA interface for brightness control */ > - if (intel_dp->edp_dpcd[0] >= DP_EDP_15) > - try_vesa_interface = true; > - > /* > * Since Intel has their own backlight control interface, the majority of machines out there > * using DPCD backlight controls with Intel GPUs will be using this interface as opposed to > @@ -694,6 +686,9 @@ int intel_dp_aux_init_backlight_funcs(struct intel_connector *connector) > * panel with Intel's OUI - which is also required for us to be able to detect Intel's > * backlight interface at all. This means that the only sensible way for us to detect both > * interfaces is to probe for Intel's first, and VESA's second. > + * > + * Also there is a chance some VBT's may advertise false Intel backlight support even if the s/VBT's/VBTs > + * tcon's DPCD says otherwise. This mean we keep VESA interface as fallback in that case. s/tcon/TCON With above nitpicks sorted, this is: Reviewed-by: Ankit Nautiyal > */ > if (try_intel_interface && intel_dp_aux_supports_hdr_backlight(connector) && > intel_dp->edp_dpcd[0] <= DP_EDP_14b) { > @@ -703,7 +698,7 @@ int intel_dp_aux_init_backlight_funcs(struct intel_connector *connector) > return 0; > } > > - if (try_vesa_interface && intel_dp_aux_supports_vesa_backlight(connector)) { > + if (intel_dp_aux_supports_vesa_backlight(connector)) { > drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Using VESA eDP backlight controls\n", > connector->base.base.id, connector->base.name); > panel->backlight.funcs = &intel_dp_vesa_bl_funcs;