Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422924AbWAMTzv (ORCPT ); Fri, 13 Jan 2006 14:55:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1422893AbWAMTzA (ORCPT ); Fri, 13 Jan 2006 14:55:00 -0500 Received: from mx2.suse.de ([195.135.220.15]:20166 "EHLO mx2.suse.de") by vger.kernel.org with ESMTP id S1422944AbWAMTyo (ORCPT ); Fri, 13 Jan 2006 14:54:44 -0500 Date: Fri, 13 Jan 2006 21:00:46 +0100 Message-ID: From: Takashi Iwai To: Pavel Machek Cc: Adam Belay , Patrick Mochel , Andrew Morton , Linux-pm mailing list , kernel list Subject: Re: [linux-pm] [patch] pm: fix runtime powermanagement's /sys interface In-Reply-To: <20060106042422.GB2496@ucw.cz> References: <20051227213439.GA1884@elf.ucw.cz> <20051227220533.GA1914@elf.ucw.cz> <20060104213405.GC1761@elf.ucw.cz> <20060107083602.GE3184@neo.rr.com> <20060107102554.GC9225@elf.ucw.cz> <20060107124544.GA3972@neo.rr.com> <20060106042422.GB2496@ucw.cz> User-Agent: Wanderlust/2.12.0 (Your Wildest Dreams) SEMI/1.14.6 (Maruoka) FLIM/1.14.7 (=?ISO-8859-4?Q?Sanj=F2?=) APEL/10.6 MULE XEmacs/21.5 (beta21) (corn) (+CVS-20050720) (i386-suse-linux) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 947 Lines: 28 At Fri, 6 Jan 2006 04:24:22 +0000, Pavel Machek wrote: > > > > > > 1.) most sound cards have more than two states. (once again latency over > > > > power savings trade offs) > > > > > > What is the latency in typical "most sound card" case? > > > > ACPI requires within 100ms for D1 and D2. D3 can be longer. > > Spec is useless here. 1usec is <100msec. Do you know any > soundcard that takes >10msec from D3? In the case of D3, the driver needs to initialize fully, and a latency longer than 10ms may easily happen espeically with HZ=100. Most of codec chips have powersave modes (disable converters and amps), so having a "powersave" state makes sense, not only "on" and "suspend". Takashi - 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/