Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754083AbZKPVAp (ORCPT ); Mon, 16 Nov 2009 16:00:45 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754050AbZKPVAo (ORCPT ); Mon, 16 Nov 2009 16:00:44 -0500 Received: from iolanthe.rowland.org ([192.131.102.54]:50488 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754046AbZKPVAn (ORCPT ); Mon, 16 Nov 2009 16:00:43 -0500 Date: Mon, 16 Nov 2009 16:00:49 -0500 (EST) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: "Rafael J. Wysocki" cc: pm list , LKML , Linux PCI , ACPI Devel Maling List , Jesse Barnes , Matthew Garrett , Oliver Neukum , Shaohua Li , Bjorn Helgaas Subject: Re: [RFC][PATCH 1/10] PM: Add flag for devices capable of generating run-time wake-up events In-Reply-To: <200911162152.38333.rjw@sisk.pl> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1686 Lines: 47 On Mon, 16 Nov 2009, Rafael J. Wysocki wrote: > On Monday 16 November 2009, Alan Stern wrote: > > On Mon, 16 Nov 2009, Rafael J. Wysocki wrote: > > > > > From: Rafael J. Wysocki > > > > > > Apparently, there are devices that can wake up the system from sleep > > > states and yet are incapable of generating wake-up events at run > > > time. Thus, introduce a flag indicating if given device is capable > > > of generating run-time wake-up events. > > > > This raises the question: Who is responsible for setting the new > > flag? The code that registers the device? > > Yes, in general. The platform. And for non-platform devices (hot-pluggable, for example)? Presumably you would want the driver that detects and registers the device to set this flag. > Actually, I needed it for PCI, but I thought it would be better to put it at > the core level. > > > What if the kernel can't tell whether or not the device can generate > > runtime wake-up events? > > Do you have any specific examples in mind? What about Matthew's example of an ACPI GPE which might or might not cause a runtime wake-up event, depending on the AML code in the BIOS? > > What if the user wants to override the kernel's setting? Should there > > be a sysfs attribute controlling the flag? > > I have no plans for adding anything like that. So if the kernel makes a mistake here, the user won't be able to correct it. Alan Stern -- 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/