From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753267Ab1AXP2k (ORCPT ); Mon, 24 Jan 2011 10:28:40 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:34370 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753002Ab1AXP2j (ORCPT ); Mon, 24 Jan 2011 10:28:39 -0500 Date: Mon, 24 Jan 2011 16:28:31 +0100 From: Ingo Molnar To: Alexander Gordeev Cc: Linus Torvalds , Andrew Morton , Linux Kernel Mailing List , Thomas Gleixner Subject: Re: [PATCH] parport: make lockdep happy with waitlist_lock Message-ID: <20110124152831.GB4416@elte.hu> References: <20110119083916.GA2166@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -2.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Alexander Gordeev wrote: > parport_unregister_device should never be used when interrupts are > enabled in hardware and irq handler is registered so there is no need > to disable interrupts when using waitlist_lock. But there is no way to > explain this subtle semantics to lockdep analyzer. So disable interrupts > here too to simplify things. The price is negligible. > > Signed-off-by: Alexander Gordeev > --- > drivers/parport/share.c | 4 ++-- > 1 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/parport/share.c b/drivers/parport/share.c > index a2d9d1e..c3dd1a3 100644 > --- a/drivers/parport/share.c > +++ b/drivers/parport/share.c > @@ -678,7 +678,7 @@ void parport_unregister_device(struct pardevice *dev) > > /* Make sure we haven't left any pointers around in the wait > * list. */ > - spin_lock (&port->waitlist_lock); > + spin_lock_irq (&port->waitlist_lock); Small detail: please use a consistent coding style, i.e. 'spin_lock_irq(', not 'spin_lock_irq ('. Thanks, Ingo