From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lars-Peter Clausen Subject: Re: [PATCH] [v2] ASoC: support all possible sample rates in the WM8776 driver Date: Fri, 16 Sep 2011 18:27:14 +0200 Message-ID: <4E7378E2.9050200@metafoo.de> References: <1316182614-9666-1-git-send-email-timur@freescale.com> <4E736F9B.6080206@freescale.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mailhost.informatik.uni-hamburg.de (mailhost.informatik.uni-hamburg.de [134.100.9.70]) by alsa0.perex.cz (Postfix) with ESMTP id 51EAE24340 for ; Fri, 16 Sep 2011 18:27:55 +0200 (CEST) In-Reply-To: <4E736F9B.6080206@freescale.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: Timur Tabi Cc: Takashi Iwai , alsa-devel@alsa-project.org, broonie@opensource.wolfsonmicro.com, lrg@ti.com List-Id: alsa-devel@alsa-project.org On 09/16/2011 05:47 PM, Timur Tabi wrote: > Takashi Iwai wrote: > >> It's not optimal from some aspects. Basically this should be resolved >> in hw_constraints, not in hw_params, so that the configurator can find >> the possible rates. Otherwise you have no idea what rate would be >> accepted. > > Yes, I was concerned about that. So should I be calling one of the > snd_pcm_hw_constraint_xxx functions in the codec's .startup function? That > would require ASoC to call the machine driver's .startup function *before* > calling the codec driver's .startup function, since the machine driver's > .startup function is where I call the codec to tell it what the mclk frequency is. > You mentioned in an earlyer mail that you can switch the sysclk rate at runtime. So setting the constraints based on the current sysclk rate won't really work. I think you need some mechanism to specify the supported rates on a per machine driver basis.