From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757362Ab0BLRDh (ORCPT ); Fri, 12 Feb 2010 12:03:37 -0500 Received: from cantor.suse.de ([195.135.220.2]:40611 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757185Ab0BLRDf (ORCPT ); Fri, 12 Feb 2010 12:03:35 -0500 Date: Fri, 12 Feb 2010 18:03:34 +0100 Message-ID: From: Takashi Iwai To: Linus Torvalds Cc: Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: [GIT PULL] sound fixes In-Reply-To: References: User-Agent: Wanderlust/2.15.6 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.7 Emacs/23.1 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) 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 Fri, 12 Feb 2010 08:51:29 -0800 (PST), Linus Torvalds wrote: > > > > On Fri, 12 Feb 2010, Takashi Iwai wrote: > > > > Jody Bruchon (1): > > ALSA: hda-intel: Avoid divide by zero crash > > I pulled, but I really think it should look more like: > > > > > --- > > sound/pci/hda/hda_intel.c | 6 ++++++ > > 1 files changed, 6 insertions(+), 0 deletions(-) > > > > diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c > > index b8faa6d..e767c3f 100644 > > --- a/sound/pci/hda/hda_intel.c > > +++ b/sound/pci/hda/hda_intel.c > > @@ -1893,6 +1893,12 @@ static int azx_position_ok(struct azx *chip, struct azx_dev *azx_dev) > > > > if (!bdl_pos_adj[chip->dev_index]) > > return 1; /* no delayed ack */ > > + if (azx_dev->period_bytes == 0) { > > + printk(KERN_WARNING > > + "hda-intel: Divide by zero was avoided " > > + "in azx_dev->period_bytes.\n"); > > + return 0; > > + } > > if (WARN_ONCE(!azx_dev->period_bytes, "hda-intel: zero azx_dev->period_bytes") > return 0; > > or something. It really doesn't want to warn multiple times, and by using > a WARN_ONCE() it will also get picked up by kerneloops etc. Ah, right. > Or if that zero period_bytes is normal under certain circumstances, then > there shouldn't be a printout at all. This zero division shouldn't happen at all. I've never seen this, and this is the first report. I suspect it being some bogus IRQ, but the fix itself doesn't do wrong, so picked it up. I'm going to fix to WARN_ONCE() quickly and send a pull request again. Thanks! Takashi