From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754363Ab2BQT3h (ORCPT ); Fri, 17 Feb 2012 14:29:37 -0500 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:60913 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754310Ab2BQT3f (ORCPT ); Fri, 17 Feb 2012 14:29:35 -0500 Date: Fri, 17 Feb 2012 20:29:28 +0100 From: Pavel Machek To: "Rafael J. Wysocki" Cc: Linux PM list , LKML , Linux-sh list , Magnus Damm , Guennadi Liakhovetski , Kevin Hilman , jean.pihet@newoldbits.com Subject: Re: [PATCH 4/7] PM / Domains: Rework system suspend callback routines Message-ID: <20120217192928.GI2707@elf.ucw.cz> References: <201111070101.33960.rjw@sisk.pl> <201111070108.11727.rjw@sisk.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201111070108.11727.rjw@sisk.pl> X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 2011-11-07 01:08:11, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > The current generic PM domains code attempts to use the generic > system suspend operations along with the domains' device stop/start > routines, which requires device drivers to assume that their > system suspend/resume (and hibernation/restore) callbacks will always > be used with generic PM domains. However, in theory, the same > hardware may be used in devices that don't belong to any PM domain, > in which case it would be necessary to add "fake" PM domains to > satisfy the above assumption. Also, the domain the hardware belongs > to may not be handled with the help of the generic code. > > To allow device drivers that may be used along with the generic PM > domains code of more flexibility, add new device callbacks, .freeze(), > .freeze_late(), .thaw_early() and .thaw(), that can be supplied by > the drivers in addition to their "standard" system suspend and > hibernation callbacks. These new callbacks, if defined, will be used > by the generic PM domains code for the handling of system suspend and > hibernation instead of the "standard" ones. This will allow drivers > to be designed to work with generic PM domains as well as without > them. Should this go to Documentation/ somewhere? May concern is that we have way too many callbacks these days. Why is fake PM domain such a bad thing? Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html