From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by alsa0.perex.cz (Postfix) with ESMTP id 2AF462614AF for ; Thu, 10 Mar 2016 14:20:33 +0100 (CET) Date: Fri, 11 Mar 2016 02:27:03 +0530 From: Jeeja KP Message-ID: <20160310205703.GA26632@jeeja.kp@intel.com> References: <20160216161747.GA18103@jeeja.kp@intel.com> <20160302020215.GN18327@sirena.org.uk> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20160302020215.GN18327@sirena.org.uk> Subject: Re: [alsa-devel] [RFD] Add hw_params support for hostless stream BE DAIs List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Mark Brown Cc: tiwai@suse.de, vinod.koul@intel.com, alsa-devel@alsa-project.org, liam.r.girdwood@intel.com, patches.audio@intel.com List-ID: On Wed, Mar 02, 2016 at 11:02:15AM +0900, Mark Brown wrote: > On Tue, Feb 16, 2016 at 09:47:47PM +0530, Jeeja KP wrote: > > We have no mechanism to configure hw_params for DAIs which are hostless. > > Like a loop or DAIs connected to internal sinks/sources. > > Please propose patches, don't send enormous design documents. They're > big, take a long time to read and don't really get us anywhere unless > they're extremely clear. Ok. I have the patches ready, will post it. > > > Approach: > > 1. Allow params to be defined for other BE dai link also. this > > currently applicable only for codec_codec link. > > Like I keep saying if you're thinking about this in terms of DPCM you're > solving the wrong problem - we already support supplying parameters for > device<->device links, we already have systems that need to configure > things for device<->device links so we can already see that if we're > doing something that only works for things that are on SoC and can use > DPCM then we're not solving the problem. No this is not exactly about DPCM. It is about the device<->device links that assume you can have only codecs as hostless and thus change the direction for the link. Since we are rendering from SoC we don't need direction change. > > DPCM works pretty well for small, simple DSPs that are mostly in line > in the middle of a standard DAI but it does have limitations which > you're now running into. Your systems don't fit well with what DPCM > supports naturally. > > > struct snd_soc_dai_link { > > const struct snd_soc_pcm_stream *params; > > unsigned int num_params; > > > > + /* flag to create codec codec based on the flag*/ > > + unsigned int codec_link:1; > > + > > This is clearly confused, if we can't figure out what the two devices we > are connecting are based on just looking at the devices then that's > really not a good sign that our interfaces are sensible and easy to work > with. Right now dai_link assumes device<->device links based on params so we cannot specify params for anything where we dont want direction change and would like to treat as normal direction dai_link. So we propose this to move to codec_link flag and use params only for creating controls based on params provided. -- _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel