From mboxrd@z Thu Jan  1 00:00:00 1970
From: linas@austin.ibm.com (Linas Vepstas)
Subject: Re: [BUG] ide dma_timer_expiry, then hard lockup
Date: Mon, 18 Jun 2007 15:46:01 -0500
Message-ID: <20070618204601.GF5836@austin.ibm.com>
References: <20070618175713.GD5836@austin.ibm.com> <20070618212704.394912b8@the-village.bc.nu>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Return-path: <linux-kernel-owner+glk-linux-kernel-3=40m.gmane.org-S932720AbXFRUqW@vger.kernel.org>
Content-Disposition: inline
In-Reply-To: <20070618212704.394912b8@the-village.bc.nu>
Sender: linux-kernel-owner@vger.kernel.org
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org
List-Id: linux-ide@vger.kernel.org

On Mon, Jun 18, 2007 at 09:27:04PM +0100, Alan Cox wrote:
> > ide_dma_timeout_retry() in ide-io.c 
> >   prints the "hdc: DMA Timeout error" then calls
> >   HWIF(drive)->ide_dma_end(drive);
> >     which returns, and then calls 
> >   hwif->INB(IDE_STATUS_REG) which is needed as an argument to ide_error()
> > 
> > But this hangs! -- The INB never returns.
> > Now:  hwif->INB = ide_inb; in ide-iops.c
> 
> Yep and the I/O cycle never completes so the box hangs. This occurs if
> the drive blows up and never switches IORDY to indicate completion. The
> hpt will also do this sometimes if it gets addled by a confused drive,
> while an intel one often won't.

So what do you suggest? (I could buy an alternate ide controller,
and hope that goes away, or just buy a different hard drive. But
that's beside the point).

I can prepare a patch, but only with a lot of guidance. I can test 
& debug, I'm highly motivated just right now ... 

--linas