From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keith Chew Subject: Re: PCM multi A/V Sync bug on SMP system Date: Wed, 28 Apr 2010 07:28:59 +1200 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-iw0-f189.google.com (mail-iw0-f189.google.com [209.85.223.189]) by alsa0.perex.cz (Postfix) with ESMTP id D9E7510383E for ; Tue, 27 Apr 2010 21:29:01 +0200 (CEST) Received: by iwn27 with SMTP id 27so6694995iwn.5 for ; Tue, 27 Apr 2010 12:29:00 -0700 (PDT) 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: alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org > > Please advise how can I track down this problem in code, happy to make > changes and test. > After further investigation on the soucecode, it appears that the default surround51 for the driver ca0106, uses "multi" to the 3 devices/outputs on the card. So "multi" does work fine on an SMP system. The timing problems are only introduced when "multi" is combined with "dmix" for 5.1 channels. I would like to help out in fixing this, but need a little bit of guidance from the experts here. Have I identified the problem correctly? Ie interaction between "multi" and "dmix" on a 5.1 channel card giving timing issues on an SMP system? If it is unlikely, I will investigate other areas. Regards Keith