Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754549AbZLIRTs (ORCPT ); Wed, 9 Dec 2009 12:19:48 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754174AbZLIRTs (ORCPT ); Wed, 9 Dec 2009 12:19:48 -0500 Received: from smtp1.linux-foundation.org ([140.211.169.13]:46064 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754008AbZLIRTr (ORCPT ); Wed, 9 Dec 2009 12:19:47 -0500 Date: Wed, 9 Dec 2009 09:19:46 -0800 (PST) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: Alan Stern cc: Mark Brown , "Rafael J. Wysocki" , Zhang Rui , LKML , ACPI Devel Maling List , pm list Subject: Re: Async resume patch (was: Re: [GIT PULL] PM updates for 2.6.33) In-Reply-To: Message-ID: References: User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1342 Lines: 32 On Wed, 9 Dec 2009, Alan Stern wrote: > > If audio _is_ being played when a suspend occurs, users probably don't > mind audible artifacts. In fact, they probably expect some. I'd say it's physically impossible not to get them. If you're really suspending your audio hardware, it _will_ be quiet ;) I suspect somebody is draining existing queues or something, or just probing for an external analog part. Neither of which is really sensible or absolutely required in an embedded suspend/resume kind of situation. Especially for STR, just "leave all the data structures around, and just stop the DMA engine" is often a perfectly fine solution - but drivers don't do it, exactly because we've often had the mentality that you re-initialize everything under the sun. I can see _why_ a driver would do that ("we re-use the same code that we use on close/open or module unload/reload"), but it doesn't change the fact that it's stupid to do if you worry about latency. And yeah, turning it async might hide the problem. But the code word there is "hide" rather than "fix". Linus -- 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/