Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934127Ab0HFAWR (ORCPT ); Thu, 5 Aug 2010 20:22:17 -0400 Received: from smtp-out.google.com ([74.125.121.35]:58984 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756530Ab0HFAWN convert rfc822-to-8bit (ORCPT ); Thu, 5 Aug 2010 20:22:13 -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:content-transfer-encoding:x-system-of-record; b=I5YxMD4SpEf9YMtKmzexfKM638Tq9Hu6lTNG9VJJdIAsif1/Tu16ICFeMw76yJL1Y ERgzucTGw8mmDL+hzOssg== MIME-Version: 1.0 In-Reply-To: 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 17:22:10 -0700 Message-ID: Subject: Re: Attempted summary of suspend-blockers LKML thread From: Brian Swetland To: david@lang.hm Cc: paulmck@linux.vnet.ibm.com, 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 Content-Transfer-Encoding: 8BIT X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1128 Lines: 24 On Thu, Aug 5, 2010 at 5:16 PM, wrote: >>> >>> 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. > > the playback is able to continue even with all the clocks stopped? that > surprises me. I would hav expected it to be able to sleep while playing > audio, but not do a full suspend. Obviously not all clocks are stopped (the DSP and codec are powered and clocked, for example), but yeah we can clock gate and power gate the cpu and most other peripherals while audio is playing on a number of ARM SoC designs available today (and the past few years). 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/