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 AE8A5C25B47 for ; Fri, 27 Oct 2023 11:10:22 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 220E410E0C2; Fri, 27 Oct 2023 11:10:22 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.93]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4017E10E0C2 for ; Fri, 27 Oct 2023 11:10:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1698405020; x=1729941020; h=from:to:subject:in-reply-to:references:date:message-id: mime-version; bh=2yjfIOGP/AcdmNZuRZxjRCYxmDAzgaM9tQSe96ZK4B0=; b=grX/mKrfv26AYcRbF7tcMXJ4BP3RLIvL05A2hQTVottpiZZlvIoAEEUV agy0sv4M4rlYN1021kTAC02mfppOhtZJG9nRqB3pnEZZNruyKmArlHE1D yT+6PBN4nAekA0HUaO7BuF1wXgoZCbDD1vDE38C4qWZjvggLbY28y2vD5 Ye9D0KUIsHBUk9eFWNg0BHdv91RXJksmZ5vYuB1Lt0hFhHA19VHj+fLPF eXImD7H2fGdEopXWYFSfSo5ENlSYU8xOclkNIunnCu7WUIsQYy4p94Haa /o8Nygio/xTtrPzGoUEARnY4OduF74GskNjwkkRZ8fdJFT5DL7EVTVVih A==; X-IronPort-AV: E=McAfee;i="6600,9927,10875"; a="384964271" X-IronPort-AV: E=Sophos;i="6.03,256,1694761200"; d="scan'208";a="384964271" Received: from orviesa001.jf.intel.com ([10.64.159.141]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Oct 2023 04:10:19 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.03,256,1694761200"; d="scan'208";a="7196310" Received: from jhajducz-mobl.ger.corp.intel.com (HELO localhost) ([10.252.34.19]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Oct 2023 04:08:55 -0700 From: Jani Nikula To: Nemesa Garg , intel-gfx@lists.freedesktop.org In-Reply-To: <20231027095336.3059445-2-nemesa.garg@intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20231027095336.3059445-1-nemesa.garg@intel.com> <20231027095336.3059445-2-nemesa.garg@intel.com> Date: Fri, 27 Oct 2023 14:10:14 +0300 Message-ID: <87v8as5njd.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Intel-gfx] [v2 1/2] drm/i915/display: Add support for darskscreen detection 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" On Fri, 27 Oct 2023, Nemesa Garg wrote: > Darkscreen detection checks if all the pixels of the frame are less then > or equal to the comparision value. The comparision value is set to 256 > i.e black. So upon getting black pixels from the pipe, the dark screen > detect bit is set and an error message will be printed. Okay, this still describes *what* the patch does, but not *why*. Why do we need this? What for? (Please just reply here for starters, instead of resending.) BR, Jani. -- Jani Nikula, Intel