From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oliver Neukum Subject: Re: [patch update] Re: Run-time PM idea (was: Re: [RFC][PATCH 0/2] PM: Rearrange core suspend code) Date: Thu, 11 Jun 2009 01:15:30 +0200 Message-ID: <200906110115.30729.oliver__27233.3535286181$1244675734$gmane$org@neukum.org> References: <200906102331.14267.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <200906102331.14267.rjw@sisk.pl> Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.linux-foundation.org Errors-To: linux-pm-bounces@lists.linux-foundation.org To: "Rafael J. Wysocki" Cc: ACPI Devel Maling List , Linux-pm mailing list , LKML List-Id: linux-pm@vger.kernel.org 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. =A0For 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. =A0In 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