From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751377Ab2KPAuv (ORCPT ); Thu, 15 Nov 2012 19:50:51 -0500 Received: from ogre.sisk.pl ([193.178.161.156]:47405 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751083Ab2KPAuu (ORCPT ); Thu, 15 Nov 2012 19:50:50 -0500 From: "Rafael J. Wysocki" To: Huang Ying Cc: Alan Stern , linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org Subject: Re: [BUGFIX] PM: Fix active child counting when disabled and forbidden Date: Fri, 16 Nov 2012 01:55:13 +0100 Message-ID: <5403446.Qq6ASJZlmy@vostro.rjw.lan> User-Agent: KMail/4.8.5 (Linux/3.7.0-rc5; KDE/4.8.5; x86_64; ; ) In-Reply-To: <193302419.NkjaAjIrYa@vostro.rjw.lan> References: <1353026174.7176.301.camel@yhuang-dev> <193302419.NkjaAjIrYa@vostro.rjw.lan> 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 Friday, November 16, 2012 01:44:00 AM Rafael J. Wysocki wrote: > On Friday, November 16, 2012 08:36:14 AM Huang Ying wrote: > > On Thu, 2012-11-15 at 10:51 +0100, Rafael J. Wysocki wrote: [...] > > > > For this situation, if user "echo auto > .../power/control" for the > > device, the runtime PM callbacks of device will be called. I think that > > is not intended. So I think it is better to use some kind of flag or > > state for that. > > I'm not sure what situation exactly you have in mind. Care to give an > exact scenario? Ah, I see. When we've just called drv->remove(), there is a window in which user space may cause the driver's runtime PM callbacks to be executed by changing its attribute to "auto". So perhaps we should check pci_dev->driver rather than pci_dev->dev.driver in the runtime PM callbacks? With a few more changes that should allow us to close that race. Thanks, Rafael -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.