From mboxrd@z Thu Jan 1 00:00:00 1970 From: Clemens Ladisch Subject: Re: Will ALSA ever call _prepare or _hw_params while it's playing? Date: Wed, 21 May 2008 17:53:38 +0200 Message-ID: <48344582.8020601@alsa-project.org> References: <4834438A.4060702@freescale.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from out1.smtp.messagingengine.com (out1.smtp.messagingengine.com [66.111.4.25]) by alsa0.perex.cz (Postfix) with ESMTP id 41593243AA for ; Wed, 21 May 2008 17:53:44 +0200 (CEST) In-Reply-To: <4834438A.4060702@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: ALSA development List-Id: alsa-devel@alsa-project.org Timur Tabi wrote: > I have an ASoC driver with a _hw_params, _prepare, and _trigger functions. I've > recently discovered that I need to keep one of my devices disabled until > playback starts. > > So I would like to know if ALSA will ever call _hw_params, _prepare, or _trigger > if playback or capture is currently in process, or will ALSA first call the > _trigger to stop/pause the driver. While a stream is running (after trigger with START), ALSA will only call the pointer or the trigger (STOP/PAUSE/SUSPEND) callbacks. Different streams are not synchronized in any way. (This also applies to the playback/capture streams of one card.) Regards, Clemens