From owner-freebsd-hackers@FreeBSD.ORG Wed Jul 14 13:56:45 2004 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 5501816A4CE for ; Wed, 14 Jul 2004 13:56:45 +0000 (GMT) Received: from comp.chem.msu.su (comp.chem.msu.su [158.250.32.97]) by mx1.FreeBSD.org (Postfix) with ESMTP id 6E02443D46 for ; Wed, 14 Jul 2004 13:56:44 +0000 (GMT) (envelope-from yar@comp.chem.msu.su) Received: from comp.chem.msu.su (localhost [127.0.0.1]) by comp.chem.msu.su (8.12.9p2/8.12.9) with ESMTP id i6EDuc6E019489; Wed, 14 Jul 2004 17:56:38 +0400 (MSD) (envelope-from yar@comp.chem.msu.su) Received: (from yar@localhost) by comp.chem.msu.su (8.12.9p2/8.12.9/Submit) id i6EDubdE019488; Wed, 14 Jul 2004 17:56:37 +0400 (MSD) (envelope-from yar) Date: Wed, 14 Jul 2004 17:56:37 +0400 From: Yar Tikhiy To: Jean-Sebastien Roy Message-ID: <20040714135637.GB18493@comp.chem.msu.su> References: <40EF172C.7020508@jeannot.org> <20040713233120.GA79064@comp.chem.msu.su> <40F52FD1.9040908@jeannot.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <40F52FD1.9040908@jeannot.org> User-Agent: Mutt/1.5.6i cc: freebsd-hackers@freebsd.org cc: marck@rinet.ru Subject: Re: Silent errors when reading CDs X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 14 Jul 2004 13:56:45 -0000 On Wed, Jul 14, 2004 at 03:06:25PM +0200, Jean-Sebastien Roy wrote: > > >Once I had an old noname PC (iP200 in an i430VX motherboard), and > >I installed a DVD+RW drive into it. Data read from a CD or DVD was > >damaged with high probability. With hw.ata.atapi_dma set to zero, > >the probability of data corruption was lower, but still noticable. > >That's while there were no corruption on burning in DMA or PIO mode. > > > At least I'm not alone ! Of course you are not! A lot of ATA users are in the same boat. I myself managed to get out of it only thanks to VIA ;-) Now I have a VIA KT133-based motherboard, which seems to have no trouble with DMA on ATAPI. Alas, it doesn't mean that other VIA chipsets have bug-free ATAPI support. Moreover, it won't guarantee that another instance of the same chipset would give you no trouble. > >Are there CDs in your collection that produce no errors? > > > Yes, but I cannot really tell if it's by chance or they really do not > produce errors. That's a point to test in order to be completely sure. Just pick such a "error-free" CD, read it *really many* a time, and compare the checksums. > The CDs read well in other computers. FWIW, my ATA controler is an Intel > ICH5 : [skip] > I think I will live with this bug until I change hardware. In any case, testing the effect of disabling atapi_dma in your system would be interesting. -- Yar