From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pierre-Louis Bossart Subject: Re: [PATCH v2] ALSA: hda/ca0132 - Update latency based on DSP state. Date: Fri, 05 Apr 2013 10:01:04 -0500 Message-ID: <515EE730.6080705@linux.intel.com> References: <1365108909-13587-1-git-send-email-dgreid@chromium.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from mga03.intel.com (mga03.intel.com [143.182.124.21]) by alsa0.perex.cz (Postfix) with ESMTP id A260A265FDA for ; Fri, 5 Apr 2013 17:01:08 +0200 (CEST) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Takashi Iwai Cc: Dylan Reid , alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org >> The DSP in the CA0132 codec adds a variable latency to audio depending >> on what processing is being done. Add a new patch op to return that >> latency for capture and playback streams. The latency is determined >> by which blocks are enabled and knowing how much latency is added by >> each block. >> >> Signed-off-by: Dylan Reid > > Thanks, applied. This conflicts with the audio timestamp stuff I contributed last year. If the hardware supports a WALLCLK, and HDA does, the timestamp is just a read of the counter plus a translation to ns. If it doesn't, the timestamp corresponds to the delay. If you modify the definition of the delay then the timestamp will be off on some platforms. -Pierre