From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756146AbZBJUZl (ORCPT ); Tue, 10 Feb 2009 15:25:41 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754813AbZBJUZc (ORCPT ); Tue, 10 Feb 2009 15:25:32 -0500 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:50856 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754742AbZBJUZb (ORCPT ); Tue, 10 Feb 2009 15:25:31 -0500 Date: Tue, 10 Feb 2009 21:25:24 +0100 From: Pavel Machek To: "Rafael J. Wysocki" Cc: Linus Torvalds , Benjamin Herrenschmidt , Linux Kernel Mailing List , Jesse Barnes , Andreas Schwab , Len Brown Subject: Re: PCI PM: Restore standard config registers of all devices early Message-ID: <20090210202524.GF1382@ucw.cz> References: <200901261904.n0QJ4Q9c016709@hera.kernel.org> <200902022333.51017.rjw@sisk.pl> <200902022356.33094.rjw@sisk.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200902022356.33094.rjw@sisk.pl> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi! > > I'll have a look at the ACPI thing. > > Generally speaking, we'd need to run acpi_evaluate_object() with interrupts > off. > > There are two apparent problems with that, from a quick look: > > * The ACPI_MTX_INTERPRETER mutex needs to be acquired, but we know we won't > need that mutex with interrupts off, so presumably we can work around this. In such case we either need refrigerator, or we should grab MTX_INTERPRETER before we start suspending, hmm. > * Memory allocations with GFP_KERNEL are made, which is even worse, because > we really shouldn't do that during suspend _at_ _all_, even during the regular > ->suspend() with interrupts on, because there's not guarantee that swap will > will be available at that time. So, for the sake of correctness, we should > get rid of the GFP_KERNEL from the ACPI code paths executed during > suspend-resume anyway. Well, we have some small reserves for stuff like that... Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html