From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753887Ab1GDIXP (ORCPT ); Mon, 4 Jul 2011 04:23:15 -0400 Received: from mail.betterlinux.com ([199.58.199.50]:54755 "EHLO mail.betterlinux.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752612Ab1GDIXN (ORCPT ); Mon, 4 Jul 2011 04:23:13 -0400 Date: Mon, 4 Jul 2011 10:23:07 +0200 From: Andrea Righi To: "Rafael J. Wysocki" Cc: Len Brown , Peter Zijlstra , Ingo Molnar , Borislav Petkov , Maciej Rutecki , Florian Mickler , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] ACPI: fix acpi_power_off lockdep splat Message-ID: <20110704082307.GA1239@thinkpad> References: <1309684450-24549-1-git-send-email-andrea@betterlinux.com> <201107032259.05722.rjw@sisk.pl> <201107040011.32254.rjw@sisk.pl> <201107040028.23569.rjw@sisk.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201107040028.23569.rjw@sisk.pl> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 04, 2011 at 12:28:23AM +0200, Rafael J. Wysocki wrote: > On Monday, July 04, 2011, Rafael J. Wysocki wrote: > > On Sunday, July 03, 2011, Rafael J. Wysocki wrote: > > > On Sunday, July 03, 2011, Andrea Righi wrote: > > > > Implement acpi_os_create_lock() as a C-preprocessor macro to suppress > > > > lockdep false positive. > > > > > > > > When lockdep is enabled the spin_lock_init macro stringifies it's > > > > argument and uses that as a name for the lock in the debugging. > > > > > > > > By executing spin_lock_init in a macro the key changes from "lock" for > > > > all locks to the actual argument of acpi_os_create_lock() > > > > ("&acpi_gbl_global_lock_pending_lock", "&acpi_gbl_gpe_lock" or > > > > "&acpi_gbl_hardware_lock" for now). > > > > > > > > This fixes: > > > > https://bugzilla.kernel.org/show_bug.cgi?id=38152 > > > > > > > > ChangeLog (v1 -> v2): > > > > - avoid to call spin_lock_init multiple times on the same lock > > > > - rewrite patch description (thanks to Florian for providing a better > > > > description of the patch) > > > > > > > > Reported-by: Borislav Petkov > > > > CC: Florian Mickler > > > > Signed-off-by: Andrea Righi > > > > --- > > > > drivers/acpi/osl.c | 3 +-- > > > > include/acpi/acpiosxf.h | 12 +++++++++++- > > > > 2 files changed, 12 insertions(+), 3 deletions(-) > > > > > > > > diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c > > > > index 52ca964..4c985d3 100644 > > > > --- a/drivers/acpi/osl.c > > > > +++ b/drivers/acpi/osl.c > > > > @@ -1336,14 +1336,13 @@ EXPORT_SYMBOL(acpi_resources_are_enforced); > > > > * Create and initialize a spinlock. > > > > */ > > > > acpi_status > > > > -acpi_os_create_lock(acpi_spinlock *out_handle) > > > > +__acpi_os_create_lock(acpi_spinlock *out_handle) > > > > { > > > > > > I would rename this to acpi_os_allocate_lock() or acpi_os_alloc_lock(), > > > so that it doesn't suggest the lock is initialized by this function. > > > > > > Hmm. There's one more thing we need to take into account here. Namely, > > > include/acpi/acpiosxf.h is used by other OSes, so we shouldn't put > > > Linux-specific stuff into it. > > > > > > I'm not sure how to work around that at the moment. > > > > OK, the patch below builds for me and seems to work even, although I haven't > > tested it with lockdep on. > > Below is a cleaned-up version, still untested with lockdep on. Tested. Works fine for me. Thanks! -Andrea