From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pierre-Louis Bossart Subject: Re: soc-dsp programming model for loopbacks Date: Thu, 26 Jan 2012 07:12:07 -0600 Message-ID: <4F215127.8050509@linux.intel.com> References: <4f1f2489.c602440a.208e.ffff9d7bSMTPIN_ADDED@mx.google.com> <1327511249.11901.37.camel@odin> <20120125171112.GR3687@opensource.wolfsonmicro.com> <002d01ccdb9c$7099f1e0$51cdd5a0$@bossart@linux.intel.com> <20120125201438.GA17032@opensource.wolfsonmicro.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mga14.intel.com (mga14.intel.com [143.182.124.37]) by alsa0.perex.cz (Postfix) with ESMTP id B11B32437C for ; Thu, 26 Jan 2012 14:12:16 +0100 (CET) In-Reply-To: <20120125201438.GA17032@opensource.wolfsonmicro.com> 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: alsa-devel@alsa-project.org, 'Liam Girdwood' List-Id: alsa-devel@alsa-project.org >> I can see how this would simplify the loopback part, but doesn't it make the >> 'regular' playback/capture functionality more complex? If my DSP is seen as >> a CODEC, how do I represent the CPU-DSP interface (DMA or shared memory)? > > You'd need a DAI for that interface but you'll need that no matter what > you do, it'll just be a very simple DAI that needs no configuration for > things like AIF format. With the soc-pcm setup you also need the front > and back end DAIs so it's about the same, the benefit comes at runtime. > My primary focus for the CODEC<->CODEC links is actually things like > basebands rather than on-SoC DSPs, it's just that if the hardware can be > thought of in the same way it should simplify things a little. Bear with me here, I am still somewhat confused. - Liam suggested either a hard-coded DAI configuration or machine driver logic to remove the need for virtual front-ends - Mark suggested to consider the DSP as a CODEC with some work to re-implement the host-dsp interface. Is this CODEC<->CODEC solution on top of the Dynamic PCM patches? Or are we talking about two completely different approaches? Thanks for your feedback -Pierre