From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: Audio:suspend to ram issue Date: Fri, 19 Aug 2011 01:25:36 +0900 Message-ID: <20110818162535.GG20208@opensource.wolfsonmicro.com> References: <4E4CABBC.20901@st.com> <4E4CEEB9.2000604@st.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from opensource2.wolfsonmicro.com (opensource.wolfsonmicro.com [80.75.67.52]) by alsa0.perex.cz (Postfix) with ESMTP id 50B5E2447D for ; Thu, 18 Aug 2011 18:25:43 +0200 (CEST) Content-Disposition: inline In-Reply-To: <4E4CEEB9.2000604@st.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: Rajeev kumar Cc: alsa-devel@alsa-project.org, lrg@slimlogic.co.uk List-Id: alsa-devel@alsa-project.org On Thu, Aug 18, 2011 at 04:21:37PM +0530, Rajeev kumar wrote: > Is there any difference between these two suspend ctrl-z and echo > mem > /sys/power/state. Yes. For example in system suspend it is likely that some of the system power supplies will be disabled and low power states will be entered which cause register contents to be lost. > While going through the alsa framework I found that suspend and > resume functionality is handled by > the framework itself.Please correct me if my understanding is not correct. DAPM will be taken care of but there is usually some other work required, if only restoring the register maps of devices. There are callbacks into the individual drivers in order to allow them to take whatever action is required to quiesce and restore the device.