From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shine Liu Subject: Re: [PATCH] ASoC: s3c24xx platform: Fix s3c2410_dma_started called at wrong time Date: Thu, 20 Aug 2009 21:38:00 +0800 Message-ID: <1250775480.1404.19.camel@sl> References: <1250761331.4412.70.camel@shinel> <20090820101549.GA23141@rakim.wolfsonmicro.main> <1250769588.3684.28.camel@sl> <20090820121851.GB11699@sirena.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from smtpbg92.qq.com (smtpbg92.qq.com [119.147.10.251]) by alsa0.perex.cz (Postfix) with SMTP id 01EE91038BC for ; Thu, 20 Aug 2009 15:38:23 +0200 (CEST) In-Reply-To: <20090820121851.GB11699@sirena.org.uk> 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: Mark Brown Cc: ben@simtec.co.uk, alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org On Thu, 2009-08-20 at 13:18 +0100, Mark Brown wrote: > > Yes, I understand the problem. The callback I suggest above ought to > allow the appropriate sequencing - the DMA driver can call the callback > to start the DAI in between starting the DMA and kicking the DMA API to > queue the next block. That would avoid the abstraction problems. > Callback is a elegant way to solve the problem. But I have a question that when should the DMA driver call the callback funtion? There is no event to tell it to call. Periodly checking? It will not only cause latency but also increase the system load. Thanks.