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 X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2C1F3CA9EAF for ; Mon, 21 Oct 2019 11:08:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0A691206C2 for ; Mon, 21 Oct 2019 11:08:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728341AbfJULIE (ORCPT ); Mon, 21 Oct 2019 07:08:04 -0400 Received: from mga17.intel.com ([192.55.52.151]:63298 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727433AbfJULID (ORCPT ); Mon, 21 Oct 2019 07:08:03 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 21 Oct 2019 04:08:02 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.67,323,1566889200"; d="scan'208";a="187507860" Received: from linux.intel.com ([10.54.29.200]) by orsmga007.jf.intel.com with ESMTP; 21 Oct 2019 04:08:02 -0700 Received: from atirumal-mobl1.amr.corp.intel.com (unknown [10.251.26.228]) by linux.intel.com (Postfix) with ESMTP id 5A59058029D; Mon, 21 Oct 2019 04:08:01 -0700 (PDT) Subject: Re: [alsa-devel] [PATCH] ASoC: bdw-rt5677: enable runtime channel merge To: "Lu, Brent" , "alsa-devel@alsa-project.org" Cc: "Rojewski, Cezary" , Liam Girdwood , Jie Yang , Mark Brown , Jaroslav Kysela , Takashi Iwai , "Zavras, Alexios" , Kuninori Morimoto , Thomas Gleixner , "linux-kernel@vger.kernel.org" References: <1570007072-23049-1-git-send-email-brent.lu@intel.com> From: Pierre-Louis Bossart Message-ID: <63da3995-b807-f9e6-6f09-a90e6b8e8e53@linux.intel.com> Date: Mon, 21 Oct 2019 05:41:55 -0500 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >> In the DAI link "Capture PCM", the FE DAI "Capture Pin" supports 4-channel >> capture but the BE DAI supports only 2-channel capture. To fix the channel >> mismatch, we need to enable the runtime channel merge for this DAI link. >> > > Hi Pierre, > > This patch is for the same issue discussed in the following thread: > https://patchwork.kernel.org/patch/11134167/ > > We enable the runtime channel merge for the DMIC DAI instead of adding a > machine driver constraint. It's working good on chrome's 3.14 branch (which > requires some backport for the runtime channel merge feature). Please let > me know if this implementation is correct for the FE/BE mismatch problem. Sorry, I don't fully understand your points, and it's the first time I see anyone use this .dpcm_merged_chan field for an Intel platform. If I look at the code I see that the core would limit the number of channels to two. But that code needs the CPU_DAI to use 2 channels, which I don't see. So is this patch self-contained or do we need an additional constraint on the FE? Thanks -Pierre