From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Ujfalusi Subject: Re: [Q] ASoC: What's the real meaning of SND_SOC_DAIFMT_NB_NF? Date: Fri, 24 Feb 2012 16:09:39 +0200 Message-ID: <4F479A23.6010307@ti.com> References: <20120223151934.GB4553@opensource.wolfsonmicro.com> <20120223161446.GA7245@opensource.wolfsonmicro.com> <4F474B97.6020407@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: Received: from na3sys009aog113.obsmtp.com (na3sys009aog113.obsmtp.com [74.125.149.209]) by alsa0.perex.cz (Postfix) with ESMTP id DAFD1104295 for ; Fri, 24 Feb 2012 15:10:03 +0100 (CET) Received: by mail-lpp01m010-f45.google.com with SMTP id i5so3943984lah.18 for ; Fri, 24 Feb 2012 06:09:43 -0800 (PST) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@alsa-project.org Errors-To: alsa-devel-bounces@alsa-project.org To: javier Martin Cc: alsa-devel@alsa-project.org, Mark Brown , Sascha Hauer , =?ISO-8859-1?Q?Eric_B=E9nard?= List-Id: alsa-devel@alsa-project.org On 02/24/2012 01:05 PM, javier Martin wrote: >> I don't think it is going to break. I would guess that the channels are >> swapped on these machines at the moment. If you correct the CPU dai >> driver the only thing that will happen is that the channels will jump in >> their correct place. > = > That would be true for stereo. However, mono should not be working right = now. The notion of mono in I2S, Left/Right Justified formats is not really valid. They are stereo protocols by design. DSP_A/B is used with mono audio (which often referred as PCM). It is the responsibility of the codec/cpu drivers to interpret the standards correctly, and configure themselves accordingly. Take a look at the Wolfson codec documentation they are really good in this matter (what I2S, DSP/PCM, and other coding means in real life). You can look at the omap-mcbsp driver for an example, but configuring the FS/BC polarity in the format selection (without taking a look at the INV mask) does not seam to be correct. -- = P=E9ter