From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Brownell Subject: Re: Re: [PATCH] swsusp: do not use pm_ops (was: Re: ...)) Date: Wed, 9 May 2007 13:21:39 -0700 Message-ID: <200705091321.39991.david-b@pacbell.net> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: 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: Alan Stern Cc: Nigel Cunningham , Pekka Enberg , Pavel Machek , linux-pm@lists.linux-foundation.org, Johannes Berg List-Id: linux-pm@vger.kernel.org > > > From the user's point of view, the differences between S4 and S5 amount to > > > just these: power consumption and availability of wakeup devices. > > > > And the fact that in S4 there's always a resumable OS image. > > Are you sure? What happens if the OSPM writes a defective, non-resumable > OS image and then goes into S4? The ACPI spec omits all such error transitions. As well as a fair number of non-error ones ... like how to enter G3. > What happens if the OS writes a resumable OS image and goes into S4, and > then the user unplugs the computer, plugs it back in, and turns the power > switch on? At that point the system must be in S5 (by definition), but > there's still a resumable image. As allowed by the chapter 2 text I pointed out earlier. S4 *always* has such an image. - Dave