From owner-freebsd-questions Thu Sep 14 11:02:49 1995 Return-Path: questions-owner Received: (from majordom@localhost) by freefall.freebsd.org (8.6.12/8.6.6) id LAA16896 for questions-outgoing; Thu, 14 Sep 1995 11:02:49 -0700 Received: from localhost.lightside.com (user38.lightside.com [198.81.209.38]) by freefall.freebsd.org (8.6.12/8.6.6) with ESMTP id LAA16879 ; Thu, 14 Sep 1995 11:02:46 -0700 Received: (from jehamby@localhost) by localhost.lightside.com (8.6.11/8.6.9) id LAA00401; Thu, 14 Sep 1995 11:03:04 -0700 Date: Thu, 14 Sep 1995 11:02:39 -0700 (PDT) From: Jake Hamby X-Sender: jehamby@localhost To: Richard Hesketh cc: hackers@freebsd.org, questions@freebsd.org Subject: Re: Does FreeBSD suffer from the Intel RZ1000 IDE bug? In-Reply-To: <21264.811096337@crane> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: questions-owner@freebsd.org Precedence: bulk On Thu, 14 Sep 1995, Richard Hesketh wrote: > I've read that Intel have a bug in their RZ1000 controller chip > found on some of their PCI motherboards (and guess what motherboard > I have 8-) This is DEFINITELY something for the FreeBSD team to verify (maybe even before 2.1.0 is released)! This IDE bug often causes the last 32 bits of data transfer to get mangled, especially if there is some other DMA transfer occurring at the same time. Fortunately, none of my computers are affected, but think of the bad publicity for FreeBSD if people start blaming it for corrupting their HD partitions! > The full details are given under: > > http://www.intel.com/procs/support/rz1000/index.html There's a white paper on this page which should be helpful to anyone who wants to patch the IDE driver, as well as a DOS detection utility for the buggy chips. > Linux is listed as being affected and I was wondering if FreeBSD > was as well or if a fixed driver is available and from what version > of FreeBSD is it in? For those interested in conspiracy theories, Intel knew about this problem for at least a year, told Microsoft about it so they could fix their drivers in Windows NT 3.51 and Windows 95, but "forgot" to tell the customers... About a serious potential source of irreparable data corruption! Silly Intel... > As a workaround I am turning off use of IDE Pre-fetch buffers > in my BIOS setup (as recommended by Intel). I'm not sure this will solve the problem for FreeBSD, since FreeBSD doesn't use the BIOS for data transfers. Also, this workaround does slow down transfer rates, while the ideal method is to patch the IDE driver to only read the status register after the data transfer is finished (see the white paper for a better description of the issue). ------------------------------------------------------------------------------ Jake Hamby | E-Mail: jehamby@lightside.com Student, Cal Poly University, Pomona | System Administrator, JPL ------------------------------------------------------------------------------