Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761182AbZFJXOv (ORCPT ); Wed, 10 Jun 2009 19:14:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756391AbZFJXOn (ORCPT ); Wed, 10 Jun 2009 19:14:43 -0400 Received: from smtp-out003.kontent.com ([81.88.40.217]:43000 "EHLO smtp-out003.kontent.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756225AbZFJXOm convert rfc822-to-8bit (ORCPT ); Wed, 10 Jun 2009 19:14:42 -0400 From: Oliver Neukum To: "Rafael J. Wysocki" Subject: Re: [patch update] Re: [linux-pm] Run-time PM idea (was: Re: [RFC][PATCH 0/2] PM: Rearrange core suspend code) Date: Thu, 11 Jun 2009 01:15:30 +0200 User-Agent: KMail/1.10.3 (Linux/2.6.27.21-0.1-default; KDE/4.1.3; x86_64; ; ) Cc: Alan Stern , "Linux-pm mailing list" , ACPI Devel Maling List , LKML References: <200906102331.14267.rjw@sisk.pl> In-Reply-To: <200906102331.14267.rjw@sisk.pl> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8BIT Content-Disposition: inline Message-Id: <200906110115.30729.oliver@neukum.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1230 Lines: 31 Am Mittwoch, 10. Juni 2009 23:31:13 schrieb Rafael J. Wysocki: > > > +/** > > > + * pm_check_children - Check if all children of a device have been > > > suspended. + * @dev: Device to check. > > > + * > > > + * Returns 0 if all children of the device have been suspended or > > > -EBUSY + * otherwise. > > > + */ > > > > We might want to do a runtime suspend even if the device's children > > aren't already suspended. ?For example, you could suspend a link while > > leaving the device on the other end of the link at full power -- > > especially if powering down the device is slow but changing the link's > > power level is fast. > > Well, this means that the dependencies between devices in the device tree > are pretty much useless for the run-time PM as far as the core is > concerned. ?In which case, why did you mention them at all? Some bussystems need this constraint others don't or only for some nodes. We need a way to communicate this to the core. Regards Oliver -- 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/