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 alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (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 CE594C43334 for ; Tue, 14 Jun 2022 16:52:05 +0000 (UTC) Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id 0B9B518BD; Tue, 14 Jun 2022 18:51:13 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 0B9B518BD DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1655225523; bh=tweFyPk/njzR5tcmhEBpD/R6XhDNmpa7aMJhnL5alkQ=; h=Date:Subject:To:References:From:In-Reply-To:Cc:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=W1Zj3Nr1Sclp0ebTbJBPvc7oC1ywSm/A8aq+C17KndlgOrMEtrHkUoHGaSy2lcb4r q5NZSBvqjpvs/WmgW3A8wMxJYtsOQoci5Pw5aLa1L1t5vH7nge2S8U/CM7s2aSY4kQ pR7k3melU05lC4+r95NT3NJ0f2mjN7rwn8HlDpJA= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id 8BB2CF80137; Tue, 14 Jun 2022 18:51:12 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 28A9AF80139; Tue, 14 Jun 2022 18:51:11 +0200 (CEST) Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id 97166F800D8 for ; Tue, 14 Jun 2022 18:51:07 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 97166F800D8 Authentication-Results: alsa1.perex.cz; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="kHjL31BB" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1655225468; x=1686761468; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=tweFyPk/njzR5tcmhEBpD/R6XhDNmpa7aMJhnL5alkQ=; b=kHjL31BBbnIH/T+KbLaZubsZ4vhIlswbOQJq71zzsLiZoVSRsSkvf+dJ NeEPUGszbxJDcB3DKJqeRTh3hVf6NWPGCwN+3s+7EfOdw18BAiOoVEGEs Fkv1t7tYiYxqJJ6wNSI1UtWLPJWbg1GY0J5L/QyfwqMPOxlydYmgCKb9f s27id6tWcnFE6CPIFfOCT/umDFLhE9EZGC3Y/s2RW57NIOTiKfOmtsz+q 41fOYbq2qA/gz3/iaOnU1roAuc53ZQY1Hp7MqEkKg139Ybwk5xFvaMKU5 Khx/WOfTY8fsQ/z+Bou1VZn2r5800ZNbg6pRNLfxZNyMNDFS2T1R/wViW A==; X-IronPort-AV: E=McAfee;i="6400,9594,10378"; a="342638963" X-IronPort-AV: E=Sophos;i="5.91,300,1647327600"; d="scan'208";a="342638963" Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Jun 2022 09:51:03 -0700 X-IronPort-AV: E=Sophos;i="5.91,300,1647327600"; d="scan'208";a="652146566" Received: from mburny-mobl1.amr.corp.intel.com (HELO [10.213.163.91]) ([10.213.163.91]) by fmsmga004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Jun 2022 09:51:02 -0700 Message-ID: <398e4885-736c-d9a9-a18d-34f69f2b63ca@linux.intel.com> Date: Tue, 14 Jun 2022 11:51:01 -0500 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Firefox/91.0 Thunderbird/91.9.1 Subject: Re: ACPI REV override for Dell XPS 13 9343 Content-Language: en-US To: Cezary Rojewski , Dominik Brodowski , "Wysocki, Rafael J" , Mark Brown References: <29a2ca0f-bc0a-04b0-d0c9-8658359d365c@intel.com> <47431e56-9acb-7c7d-307f-83d81956ec5c@linux.intel.com> From: Pierre-Louis Bossart In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Hans de Goede , "alsa-devel@alsa-project.org" , Takashi Iwai X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: "Alsa-devel" >>> It's been a while since catpt-driver [1] has been introduced to provide >>> full support for Broadwell (BDW) machines with Intel DSP. For BDW, audio >>> devices can make use of DSP only in I2S mode. In 2015 Rafael and Dominik >>> provided quirk [2] for Dell XPS 13 9343. Given the description: >>> >>> _For example, based on what ACPI exports as the supported revision, Dell >>> XPS 13 (2015) configures its audio device to either work in HDA mode or >>> in I2S mode, where the former is supposed to be used on Linux until the >>> latter is fully supported (in the kernel as well as in user space)._ >>> >>> It's clear that such configuration was not fully supported back then. I >>> believe now it is. Perhaps it is time to let the quirk in mention go? By >>> that I mean just the relevant entry, not the ACPI_REV_OVERRIDE_POSSIBLE >>> functionality as a whole. >> >> This should be a distribution or power-user decision to enable the I2S >> version IMHO. >> >> There is nothing new in terms of functionality with the I2S version, so >> limited added-value that doesn't offset the added risk due to the >> dependencies on mixer settings that may or may not be installed (UCM, >> etc). >> >> If it ain't broke don't fix it. to clarify: the HDaudio mode works just fine, there are currently zero issues or missing functionality reported by users. > Not much of a fan of the last statement. I believe challenging status > quo is the right thing to do. We do not want to bloat the kernel with > unnecessary quirks. > > The broadwell-rt286 UCM is part of alsa-ucm-conf repo for years now. The hardware supports two modes (HDaudio and DSP + I2S), the former has been in use without any issues for years. Even if you make DSP + I2S the default, you've got to leave HDaudio as a fallback, so there would be no change at the kernel level. It' very very hard to remove stuff, and in this case there is limited evidence that distributions use the DSP + I2S mode. You could deprecate the ACPI_OVERRIDE but you've got to leave time for distributions to switch. Challenging the status quo is great, but let's keep downstream in mind, shall we? The only option we removed was Medfield several years ago, but we had clear evidence that no one would be affected by such a change in the upstream kernel.