Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934335AbYBUAPX (ORCPT ); Wed, 20 Feb 2008 19:15:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932092AbYBUAOz (ORCPT ); Wed, 20 Feb 2008 19:14:55 -0500 Received: from ogre.sisk.pl ([217.79.144.158]:33249 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933517AbYBUAOx (ORCPT ); Wed, 20 Feb 2008 19:14:53 -0500 From: "Rafael J. Wysocki" To: Linus Torvalds Subject: Re: 2.6.25-rc2 System no longer powers off after suspend-to-disk. Screen becomes green. Date: Thu, 21 Feb 2008 01:13:04 +0100 User-Agent: KMail/1.9.6 (enterprise 20070904.708012) Cc: Jesse Barnes , Jeff Chua , lkml , Dave Airlie , linux-acpi@vger.kernel.org, suspend-devel List , Greg KH , Alexey Starikovskiy References: <200802210035.14058.rjw@sisk.pl> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200802210113.05733.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1871 Lines: 43 On Thursday, 21 of February 2008, Linus Torvalds wrote: > > On Thu, 21 Feb 2008, Rafael J. Wysocki wrote: > > > > In fact we have acpi_pci_choose_state() that tells the driver which power > > state to put the device into in ->suspend(). If that is used, the device ends > > up in the state expected by to BIOS for S4. > > First off, nobody should *ever* use that directly anyway. Yes, sorry. > Secondly, the one that people should use ("pci_choose_state()") doesn't > actually do what you claim it does. It does all kinds of wrong things, and > doesn't even take the target state into account at all. So look again. Well, if platform_pci_choose_state() is defined, pci_choose_state() returns its result and on ACPI systems that points to acpi_pci_choose_state(), so in fact it does what I said (apart from the error path). > > No. Again, if there are devices that wake us up from S4, but not from S5, > > they need to be handled differently in the *enter S4* case (hibernation) and > > in the *enter S5* case (powering off the system). > > And again, what does this have to do with (the example I used) the > graphics hardware? Answer: nothing. The example I gave you we simply DO > THE WRONG THING FOR. > > Same thing for things like USB devices - where pci_choose_state() doesn't > work to begin with. Why do we call "suspend()" on such a thing when we > don't want to suspend it? We shouldn't. We should call "freeze/unfreeze" > (which are no-ops) and then finally perhaps "poweroff", and that final > stage might want to spin things down or similar. I'm already convinced, really. :-) Thanks, Rafael -- 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/