From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Eremin-Solenikov Subject: Re: pxa2xx-pcm and dma_request Date: Wed, 13 May 2009 08:43:05 +0400 Message-ID: References: <87vdo6c9pt.fsf@free.fr> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-bw0-f215.google.com (mail-bw0-f215.google.com [209.85.218.215]) by alsa0.perex.cz (Postfix) with ESMTP id CDC5110387D for ; Wed, 13 May 2009 06:43:05 +0200 (CEST) Received: by bwz11 with SMTP id 11so427436bwz.32 for ; Tue, 12 May 2009 21:43:05 -0700 (PDT) In-Reply-To: <87vdo6c9pt.fsf@free.fr> 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: Robert Jarzmik Cc: alsa-devel@alsa-project.org, Mark Brown List-Id: alsa-devel@alsa-project.org 2009/5/13 Robert Jarzmik : > Hi Mark and Dimitry, > > I've been playing for some time with DMA on the PXA series. I was wondering if > the behaviour of pxa2xx-pcm is correct. > > As far as I understand, in an asoc context, the __pxa2xx_pcm_open() is called, > while in "arm context", pxa2xx_pcm_open() is called, which calls > __pxa2xx_pcm_open(). > > This was introduced by commit a6d77317678148c973bb0131cc5a3a772f756d23 I think. > > One main difference is that in "arm context", pxa_dma_request() is called, while > in "asoc context", it is not. This was done by intent as before code merge plain ARM driver used DMA while ASoC didn't. That was done mainly because I didn't have all the hw variants (only pxa255 at hand) and didn't want to introduce any points of possible failure. Now merging DMA code into generic code path would be a nice feature though. > I'd like one of you to cross-check, as I must admit I'm not following all the > impacts of the pcm code split-up. The initial impact of the merge should be void, as it was an _unification_ of code presented in ASoC and non-ASoC drivers. -- With best wishes Dmitry