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 755F8CCD1BF for ; Tue, 28 Oct 2025 19:08:17 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D84F610E10C; Tue, 28 Oct 2025 19:08:16 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="Fy0xIUyH"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.12]) by gabe.freedesktop.org (Postfix) with ESMTPS id 9CD2A10E10C for ; Tue, 28 Oct 2025 19:08:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1761678496; x=1793214496; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version:content-transfer-encoding; bh=sgu3/CBYH5lnx9Jj/XwSp9HOv7LXumvHgIm7Ct6sxkA=; b=Fy0xIUyHbuK2KF/PoEKajIjqj7w366l4hxhpUV3CSQ+ET65M8q3Ktrza NKYtqlGpoeI4az7IhouV5SG2NSzVA276w5HD3W5biHPdVOgAZxOmNa8XI tiKypX3TijXDqeChRgcqgtTPFXGaaRDwJPicr5x5OLMoGXnSfo3jEPwyA QEKmWV9qVeqDKe5O0NcDtd8gJFtWFYrePjCBIXAnipYZPvaAKrLsX5+ZY Ig3kWSE2PveEScHiy9+rgErtbcfTnw6UxBDYI9shLPKFrsARV8m4fZjTo YFZZrayzBeZTS+V65iuCJw7AerYAXOXGJoG1/qC7HIDt07p4hKtrUodZr w==; X-CSE-ConnectionGUID: +2nGOppySeOOaIJ3otS9aw== X-CSE-MsgGUID: 38ViWsKcQuine1cqtFs09A== X-IronPort-AV: E=McAfee;i="6800,10657,11586"; a="75237444" X-IronPort-AV: E=Sophos;i="6.19,261,1754982000"; d="scan'208";a="75237444" Received: from fmviesa003.fm.intel.com ([10.60.135.143]) by orvoesa104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Oct 2025 12:08:16 -0700 X-CSE-ConnectionGUID: a7OJqYOUQOm8RyCebGIfmA== X-CSE-MsgGUID: WtZxcn0cQs+Pmv5T/EbqwQ== X-ExtLoop1: 1 Received: from slindbla-desk.ger.corp.intel.com (HELO localhost) ([10.245.246.90]) by fmviesa003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Oct 2025 12:08:13 -0700 From: Jani Nikula To: Tiago Martins =?utf-8?Q?Ara=C3=BAjo?= Cc: Dave Airlie , dri-devel@lists.freedesktop.org, simona@ffwll.ch, mpearson-lenovo@squebb.ca Subject: Re: DisplayID checksum validation blocking hardware capabilities - CSO T3 panel In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <54375f5e6c5290aa218812c489ffe88e594217bd@intel.com> Date: Tue, 28 Oct 2025 21:08:10 +0200 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Mon, 15 Sep 2025, Tiago Martins Ara=C3=BAjo wrote: >> That's not the complete EDID data, though. It's missing 6*16 bytes. If >> you go by the hex offsets, 0x100 does not follow 0x090. > >> please grab the EDID from sysfs. > > Fresh from my terminal: > =E2=9E=9C ~ cat /sys/class/drm/card1-eDP-1/edid | edid-decode > edid-decode (hex): > > 00 ff ff ff ff ff ff 00 0e 6f 16 14 00 00 00 00 > 00 20 01 04 b5 1e 13 78 03 21 15 a8 53 49 9c 25 > 0f 50 54 00 00 00 01 01 01 01 01 01 01 01 01 01 > 01 01 01 01 01 01 ce 87 40 a0 b0 08 6a 70 30 20 > 36 00 2d bc 10 00 00 18 00 00 00 fd 00 28 78 e5 > e5 46 01 0a 20 20 20 20 20 20 00 00 00 fe 00 43 > 53 4f 54 20 54 33 0a 20 20 20 20 20 00 00 00 fe > 00 4d 4e 45 30 30 37 5a 41 31 2d 35 0a 20 01 af > > 70 13 79 00 00 03 01 14 9a 0f 01 05 3f 0b 9f 00 > 2f 00 1f 00 07 07 69 00 02 00 05 00 00 00 00 00 > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f0 98 > > ---------------- > > Block 0, Base EDID: > EDID Structure Version & Revision: 1.4 > Vendor & Product Identification: > Manufacturer: CSO > Model: 5142 > Made in: 2022 > Basic Display Parameters & Features: > Digital display > Bits per primary color channel: 10 > DisplayPort interface > Maximum image size: 30 cm x 19 cm > Gamma: 2.20 > Supported color formats: RGB 4:4:4 > First detailed timing includes the native pixel format and preferred > refresh rate > Display supports continuous frequencies > Color Characteristics: > Red : 0.6562, 0.3261 > Green: 0.2851, 0.6103 > Blue : 0.1445, 0.0595 > White: 0.3134, 0.3291 > Established Timings I & II: none > Standard Timings: none > Detailed Timing Descriptors: > DTD 1: 2880x1800 60.000966 Hz 16:10 114.362 kHz 347.660000 M= Hz > (301 mm x 188 mm) > Hfront 48 Hsync 32 Hback 80 Hpol N > Vfront 3 Vsync 6 Vback 97 Vpol N > Display Range Limits: > Monitor ranges (Range Limits Only): 40-120 Hz V, 229-229 kHz H, max > dotclock 700 MHz > Alphanumeric Data String: 'CSOT T3' > Alphanumeric Data String: 'MNE007ZA1-5' > Extension blocks: 1 > Checksum: 0xaf > > ---------------- > > Block 1, DisplayID Extension Block: > Version: 1.3 > Extension Count: 0 > Display Product Type: Extension Section > Video Timing Modes Type 1 - Detailed Timings Data Block: > DTD: 2880x1800 120.000207 Hz 16:10 228.720 kHz 695.310000 MHz > (aspect 16:10, no 3D stereo) > Hfront 48 Hsync 32 Hback 80 Hpol N > Vfront 3 Vsync 6 Vback 97 Vpol N > Checksum: 0xf0 (should be 0xf8) > Checksum: 0x98 There's an i915 bug report [1] on what is likely a similar Lenovo model to yours, with the same display, but with an Intel GPU. I looked at adding an EDID quirk for this, but actually passing the information all the way down to the DisplayID checksum validation is going to be annoying. :( BR, Jani. [1] https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/14703 --=20 Jani Nikula, Intel