Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935085Ab0HFANl (ORCPT ); Thu, 5 Aug 2010 20:13:41 -0400 Received: from smtp-out.google.com ([74.125.121.35]:55322 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755831Ab0HFANj (ORCPT ); Thu, 5 Aug 2010 20:13:39 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=mime-version:in-reply-to:references:date:message-id:subject:from:to: cc:content-type:x-system-of-record; b=UV0B2e71suKZW4KKhkJtIDzHhoWz/BRXZmg6ZSSiLysiPOyLBPopxDW2taMsWzVI/ z28cn9RGzvSszirGpcTTA== MIME-Version: 1.0 In-Reply-To: <20100805230304.GQ2447@linux.vnet.ibm.com> References: <20100805004802.GP24163@linux.vnet.ibm.com> <20100805151211.GA10080@linux.vnet.ibm.com> <20100805203102.GN2447@linux.vnet.ibm.com> <20100805230304.GQ2447@linux.vnet.ibm.com> Date: Thu, 5 Aug 2010 17:13:14 -0700 Message-ID: Subject: Re: Attempted summary of suspend-blockers LKML thread From: Brian Swetland To: paulmck@linux.vnet.ibm.com Cc: david@lang.hm, kevin granade , =?UTF-8?B?QXJ2ZSBIasO4bm5ldsOlZw==?= , Matthew Garrett , "Rafael J. Wysocki" , Arjan van de Ven , linux-pm@lists.linux-foundation.org, linux-kernel@vger.kernel.org, pavel@ucw.cz, florian@mickler.org, stern@rowland.harvard.edu, peterz@infradead.org, tglx@linutronix.de, alan@lxorguk.ukuu.org.uk Content-Type: text/plain; charset=UTF-8 X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1407 Lines: 32 On Thu, Aug 5, 2010 at 4:03 PM, Paul E. McKenney wrote: >> > so what would wake a phone up from suspend where the phone should go back to >> > sleep in under a second? >> >> Here are some real-world examples from shipped android devices: >> - battery gauging happens every 10 minutes, need to wake long enough >> to chatter with the 1w interface and make sure the battery is not >> exploding >> - always on mail/im/calendar/etc sync often has network events that >> happen every 5-10 minutes which cause devices to briefly wake up and >> return to sleep >> - gps tracker app might wake every couple minutes or every n gps >> events to log location >> - low power audio subsystems can wake you up every 1-4 seconds (pcm) >> or 1-4 minutes (mp3) to fetch more data > > Interesting! > > So for an mp3 playback, does an Android suspend between data fetches? It can if the latency is long enough (which is why I point out low power audio which is usually high latency). For low latency (system sounds, etc) 10-25ms between buffers it's not practical to fully suspend but we will go to the lowest power state in idle if possible. Brian -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/