From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Henningsson Subject: UCM/DAPM - saving power when idle? Date: Thu, 01 Nov 2012 11:39:01 +0100 Message-ID: <50925145.4070706@canonical.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from youngberry.canonical.com (youngberry.canonical.com [91.189.89.112]) by alsa0.perex.cz (Postfix) with ESMTP id A25D5261720 for ; Thu, 1 Nov 2012 11:39:02 +0100 (CET) Received: from [91.224.175.20] (helo=[10.155.5.236]) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1TTsAw-0001Kh-8F for alsa-devel@alsa-project.org; Thu, 01 Nov 2012 10:39:02 +0000 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: alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org I don't deal much with ASoC, so sorry if I'm missing something obvious here... When a certain use case is activated, that would then activate some DAPM widgets, causing the codec to consume more power. So, we should essentially avoid this unless we're actually playing back/recording. But, why isn't there a "disable all use cases" command, or possibly an "idle" command? (That, essentially, e g pulseaudio should set whenever playback/recording stops) Or; the option would be that the codec is actually powered down, but only activates itself when there is a stream; but this looks like it could cause problem with loopback paths (e g listening to FM radio, where there are no streams passing through CPU/main memory). -- David Henningsson, Canonical Ltd. https://launchpad.net/~diwic