Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760436AbZCPU0V (ORCPT ); Mon, 16 Mar 2009 16:26:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758469AbZCPU0J (ORCPT ); Mon, 16 Mar 2009 16:26:09 -0400 Received: from mx1.wp.pl ([212.77.101.5]:54324 "EHLO mx1.wp.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758353AbZCPU0I (ORCPT ); Mon, 16 Mar 2009 16:26:08 -0400 Date: Mon, 16 Mar 2009 21:32:25 +0100 From: Krzysztof Helt To: Lubomir Rintel Cc: Linux Kernel Mailing List , linux-sound@vger.kernel.org, stable@kernel.org, Andrew Morton Subject: Re: [PATCH] Fix NULL dereference when suspending snd_opl3sa2 Message-Id: <20090316213225.5d59aca1.krzysztof.h1@wp.pl> In-Reply-To: <1237212968.11067.3.camel@localhost.localdomain> References: <1237197709.7210.2.camel@localhost.localdomain> <1237212968.11067.3.camel@localhost.localdomain> X-Mailer: Sylpheed 2.4.3 (GTK+ 2.11.0; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-WP-AV: skaner antywirusowy poczty Wirtualnej Polski S. A. X-WP-SPAM: NO 0000000 [AeN0] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2866 Lines: 102 On Mon, 16 Mar 2009 15:16:08 +0100 Lubomir Rintel wrote: > On Mon, 2009-03-16 at 11:01 +0100, Lubomir Rintel wrote: > > This should fix the following OOPS: > > http://www.kerneloops.org/raw.php?rawid=80591&msgid= > > This is the same issue, with 2.6.28: > http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=519939 > > One should no force loading of the snd-opl3sa2 driver in the above cases. It was forced as the opl3sa2 is a PnP chip and the drivers were loaded as plain ISA devices. However, this is not a cause of the OOPS. The cause is that despite the driver returns -ENODEV, the higher layer hides it and the driver is bound to the bus. I suppose, the suspend and resume functions are called on it. Look at the ISA probe function: static int __devinit snd_opl3sa2_isa_probe(struct device *pdev, unsigned int dev) { struct snd_card *card; int err; card = snd_opl3sa2_card_new(dev); if (! card) return -ENOMEM; snd_card_set_dev(card, pdev); if ((err = snd_opl3sa2_probe(card, dev)) < 0) { snd_card_free(card); return err; } dev_set_drvdata(pdev, card); return 0; } If the probe function fails, the drvdata is never set to the snd_card structure pointer. The patch below should fix suspend and resume functions. Regards, Krzysztof PS. It is the same situation for PnP and BIOS PnP probing in this driver. --- Fix the OOPS during a opl3sa2 card suspend and resume if the driver is loaded but the card is not found. Signed-off-by: Krzysztof Helt --- a/sound/isa/opl3sa2.c~ 2008-10-13 18:03:52.000000000 +0200 +++ b/sound/isa/opl3sa2.c 2009-03-16 21:20:30.841348261 +0100 @@ -550,21 +550,27 @@ static int __devinit snd_opl3sa2_mixer(s #ifdef CONFIG_PM static int snd_opl3sa2_suspend(struct snd_card *card, pm_message_t state) { - struct snd_opl3sa2 *chip = card->private_data; + if (card) { + struct snd_opl3sa2 *chip = card->private_data; - snd_power_change_state(card, SNDRV_CTL_POWER_D3hot); - chip->wss->suspend(chip->wss); - /* power down */ - snd_opl3sa2_write(chip, OPL3SA2_PM_CTRL, OPL3SA2_PM_D3); + snd_power_change_state(card, SNDRV_CTL_POWER_D3hot); + chip->wss->suspend(chip->wss); + /* power down */ + snd_opl3sa2_write(chip, OPL3SA2_PM_CTRL, OPL3SA2_PM_D3); + } return 0; } static int snd_opl3sa2_resume(struct snd_card *card) { - struct snd_opl3sa2 *chip = card->private_data; + struct snd_opl3sa2 *chip; int i; + if (!card) + return 0; + + chip = card->private_data; /* power up */ snd_opl3sa2_write(chip, OPL3SA2_PM_CTRL, OPL3SA2_PM_D0); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/