From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755433Ab3AWNzE (ORCPT ); Wed, 23 Jan 2013 08:55:04 -0500 Received: from hydra.sisk.pl ([212.160.235.94]:51811 "EHLO hydra.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755227Ab3AWNzA (ORCPT ); Wed, 23 Jan 2013 08:55:00 -0500 From: "Rafael J. Wysocki" To: Greg Kroah-Hartman Cc: ACPI Devel Maling List , LKML , "Kristen C. Accardi" , Len Brown Subject: Re: [PATCH 4/4] ACPI / PM: Expose lists of device power resources to user space Date: Wed, 23 Jan 2013 15:01:02 +0100 Message-ID: <1463058.nlhMLeRgna@vostro.rjw.lan> User-Agent: KMail/4.9.5 (Linux/3.8.0-rc4; KDE/4.9.5; x86_64; ; ) In-Reply-To: <20130123010550.GB2024@kroah.com> References: <3307415.pdOY6ovZLa@vostro.rjw.lan> <3211997.SUlOUD0HDl@vostro.rjw.lan> <20130123010550.GB2024@kroah.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday, January 22, 2013 05:05:50 PM Greg Kroah-Hartman wrote: > On Wed, Jan 23, 2013 at 01:28:40AM +0100, Rafael J. Wysocki wrote: > > On Wednesday, January 23, 2013 01:17:47 AM Rafael J. Wysocki wrote: > > > On Wednesday, January 23, 2013 01:08:54 AM Rafael J. Wysocki wrote: > > > > On Tuesday, January 22, 2013 03:56:24 PM Greg Kroah-Hartman wrote: > > > > > On Tue, Jan 22, 2013 at 03:28:23AM +0100, Rafael J. Wysocki wrote: > > > > > > [...] > > > > > > > > Oh, and same question about racing userspace, you will have problems > > > > > here in that the symlinks will be showing up after the device is > > > > > created. Perhaps, to make the whole thing easier, you just change the > > > > > acpi core code to hold off on the notification until you get all of > > > > > these links and files set up and then tell userspace. That's probably > > > > > an easier fix. > > > > > > > > I suppose so. > > > > > > > > How can I do that? > > > > > > Should I set dev->kobj.uevent_suppress before calling device_register() and > > > then clear it and call the kobject_uevent(&dev->kobj, KOBJ_ADD) from the ACPI > > > core after device_register() has returned and the files have been created? > > > > I suppose along the lines of how firmware_class.c uses uevent_suppress? > > > > Is there any safe mechanism for adding/removing sysfs attributes after > > kobject_uevent(&dev->kobj, KOBJ_ADD) has been called for the given device? > > Not really. There is the KBOJ_CHANGE event that some subsystems use > (hey look, ACPI already uses it), but that's usually used to tell > userspace that the kobject has somehow "changed" status, just adding the > initial files to it seems like a gratuitous "change", right? Sure, that was a general question. :-) Thanks, Rafael -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.