From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Mack Subject: Re: ALSA - Channel swap Date: Tue, 19 Aug 2014 18:13:47 +0200 Message-ID: <53F377BB.90309@zonque.org> References: <53F35310.2040300@tcz.cz> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail.zonque.de (svenfoo.org [82.94.215.22]) by alsa0.perex.cz (Postfix) with ESMTP id 0B60D26565E for ; Tue, 19 Aug 2014 18:13:49 +0200 (CEST) In-Reply-To: <53F35310.2040300@tcz.cz> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Tomas Matejka , alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org On 08/19/2014 03:37 PM, Tomas Matejka wrote: > Good afternoon, > i have a problem: > I use sound codec CS4202, which I control with AT91SAM9263. > I'm using ALSA sound library. When i use CAPTURE mode, sometimes it > swaps left and right channel. > I have found this discussions on Internet, where is described similar > problem: > > http://pl.it-usenet.org/thread/17996/3593/ > http://sinustrom.info/2013/03/21/atmel-soc-ssc-channel-swapping/ > > I have figured out, that the problem could be in driver or in ALSA > library. Have you any solution ? Did you encountered similar problem ? When the mismatch happens, you'll certainly have wrong data on the I2S bus, so that bug cannot be caused by the codec driver. The most likely reason is that the platform's (AT91SAM9263) ASoC implementation has a problem syncing up the playback and record streams, probably in its DMA bits. I'd start searching in that area. I personally never worked with this platform, but for anyone else to help you, you should provide more information, such as the kernel version you're working with. Daniel