From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754177AbZGSMDa (ORCPT ); Sun, 19 Jul 2009 08:03:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753573AbZGSMD2 (ORCPT ); Sun, 19 Jul 2009 08:03:28 -0400 Received: from cantor.suse.de ([195.135.220.2]:36534 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753529AbZGSMD1 (ORCPT ); Sun, 19 Jul 2009 08:03:27 -0400 Date: Sun, 19 Jul 2009 14:03:26 +0200 Message-ID: From: Takashi Iwai To: Julia Lawall Cc: perex@perex.cz, alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [PATCH 6/6] sound/isa: convert nested spin_lock_irqsave to spin_lock In-Reply-To: References: User-Agent: Wanderlust/2.12.0 (Your Wildest Dreams) SEMI/1.14.6 (Maruoka) FLIM/1.14.7 (=?ISO-8859-4?Q?Sanj=F2?=) APEL/10.6 Emacs/22.3 (x86_64-suse-linux-gnu) MULE/5.0 (SAKAKI) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org At Sat, 18 Jul 2009 17:26:14 +0200 (CEST), Julia Lawall wrote: > > From: Julia Lawall > > If spin_lock_irqsave is called twice in a row with the same second > argument, the interrupt state at the point of the second call overwrites > the value saved by the first call. Indeed, the second call does not need > to save the interrupt state, so it is changed to a simple spin_lock. > > The semantic match that finds this problem is as follows: > (http://www.emn.fr/x-info/coccinelle/) > > // > @@ > expression lock1,lock2; > expression flags; > @@ > > *spin_lock_irqsave(lock1,flags) > ... when != flags > *spin_lock_irqsave(lock2,flags) > // > > Signed-off-by: Julia Lawall Applied now. Thanks. Takashi > > --- > sound/isa/gus/gus_pcm.c | 4 ++-- > 1 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/sound/isa/gus/gus_pcm.c b/sound/isa/gus/gus_pcm.c > index edb11ee..2dcf45b 100644 > --- a/sound/isa/gus/gus_pcm.c > +++ b/sound/isa/gus/gus_pcm.c > @@ -795,13 +795,13 @@ static int snd_gf1_pcm_volume_put(struct snd_kcontrol *kcontrol, struct snd_ctl_ > if (!(pcmp->flags & SNDRV_GF1_PCM_PFLG_ACTIVE)) > continue; > /* load real volume - better precision */ > - spin_lock_irqsave(&gus->reg_lock, flags); > + spin_lock(&gus->reg_lock); > snd_gf1_select_voice(gus, pvoice->number); > snd_gf1_ctrl_stop(gus, SNDRV_GF1_VB_VOLUME_CONTROL); > vol = pvoice == pcmp->pvoices[0] ? gus->gf1.pcm_volume_level_left : gus->gf1.pcm_volume_level_right; > snd_gf1_write16(gus, SNDRV_GF1_VW_VOLUME, vol); > pcmp->final_volume = 1; > - spin_unlock_irqrestore(&gus->reg_lock, flags); > + spin_unlock(&gus->reg_lock); > } > spin_unlock_irqrestore(&gus->voice_alloc, flags); > return change; >