From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752603AbdIESKs (ORCPT ); Tue, 5 Sep 2017 14:10:48 -0400 Received: from mail-pg0-f65.google.com ([74.125.83.65]:37457 "EHLO mail-pg0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752075AbdIESKo (ORCPT ); Tue, 5 Sep 2017 14:10:44 -0400 X-Google-Smtp-Source: ADKCNb4Y2v07JZe/Dzfm5zmRelXNDY+sQdAzrDZOh1hLSIcGYmFNhJX2tGiMZf3JSPjwE21ALfxVlg== Date: Tue, 5 Sep 2017 11:11:09 -0700 From: Nicolin Chen To: =?utf-8?Q?=C5=81ukasz?= Majewski Cc: Fabio Estevam , Timur Tabi , Xiubo Li , Liam Girdwood , Mark Brown , Jaroslav Kysela , Takashi Iwai , "festevam@gmail.com" , "alsa-devel@alsa-project.org" , "linuxppc-dev@lists.ozlabs.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Message-ID: <20170905181108.GB23906@Asurada-Nvidia> References: <1504436701-20700-1-git-send-email-lukma@denx.de> <07e54d28-3bbc-aad2-146b-30867c0bc337@denx.de> <20170905052031.GB2774@Asurada-CZ80> <819784e1-910b-6833-997a-2097e147bd0c@denx.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <819784e1-910b-6833-997a-2097e147bd0c@denx.de> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 05, 2017 at 10:35:34AM +0200, Łukasz Majewski wrote: > >And apparently, we shouldn't set bitclk to 66MHz either. Can > >you help to find where this 66MHz comes from? > 2. int asoc_simple_card_init_dai() @ simple-card-utils.c Oh, I just searched in the simple-card.c but missed this file. > In this function (point 2.) the > simple_dai->sysclk is set and: > snd_soc_dai_set_sysclk(dai, 0, simple_dai->sysclk, 0) > which sets frequency to 66 MHz [*]. > > The asoc_simple_card_init_dai() is called in > asoc_simple_card_dai_init() @ simple-card.c > which is assigned to dai_link->init > dai_link->init = asoc_simple_card_dai_init; @ simple_card.c > > And the sysclk itself is defined at: > ------------------------------------- > dai_props->codec_dai->sysclk, which is used at:a Why codec_dai? Why not dai_props->cpu_dai->sysclk since we are talking about SSI? > asoc_simple_card_startup(), asoc_simple_card_shutdown() and others > functions at simple-card.c > It is setup at: > asoc_simple_card_parse_clk() @ simple-card-utils.c from macro: > #define asoc_simple_card_parse_clk_cpu() > And the problem is: > ------------------- > > At the > asoc_simple_card_parse_clk() > we finally go to dts node: > /soc/aips-bus@02100000/i2c@021a0000/tfa9879@6C This tfa9879 should be the CODEC right? > which has clock from I2C (66 MHz). You mean I2C scl or I2S sclk? ----------------------------------------------------------------- But anyway, I feel very confused here as you have 66MHz clock rate (regardless of it purpose) for a codec dai but it's been passed to a cpu dai (SSI). > [*] - I could workaround this problem by setting: > > system-clock-frequency = <0> in > > dailink_master: cpu { > sound-dai = <&ssi2>; > }; > > but this is IMHO even worse hack.... than this patch. I haven't used simple-card for a while so I forgot how to define its DT bindings specifically. But you should assign ssi2 as the CPU dai and assign tfa9879 as a CODEC dai.