From owner-freebsd-questions Wed Dec 4 10:32:28 1996 Return-Path: owner-questions Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id KAA14750 for questions-outgoing; Wed, 4 Dec 1996 10:32:28 -0800 (PST) Received: from who.cdrom.com (who.cdrom.com [204.216.27.3]) by freefall.freebsd.org (8.7.5/8.7.3) with ESMTP id KAA14739 for ; Wed, 4 Dec 1996 10:32:25 -0800 (PST) Received: from xmission.xmission.com (softweyr@xmission.xmission.com [198.60.22.2]) by who.cdrom.com (8.7.5/8.6.11) with ESMTP id KAA00342 for ; Wed, 4 Dec 1996 10:32:20 -0800 (PST) Received: (from softweyr@localhost) by xmission.xmission.com (8.8.3/8.7.5) id LAA27958; Wed, 4 Dec 1996 11:29:28 -0700 (MST) From: Softweyr LLC Message-Id: <199612041829.LAA27958@xmission.xmission.com> Subject: Re: 2.1.5R: aha0: DMA beyond end of ISA ? To: questions@freefall.freebsd.org Date: Wed, 4 Dec 1996 11:29:28 -0700 (MST) Cc: mikebo@tellabs.com In-Reply-To: <199612041658.IAA00184@freefall.freebsd.org> from "owner-questions-digest@freefall.freebsd.org" at Dec 4, 96 08:58:50 am X-Mailer: ELM [version 2.4 PL25] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-questions@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk mikebo@tellabs.com lamented: > I have just put together a new Pentium PCI system with an Adaptec 2940U. > I had the Adaptec 1542B ISA card left over, so I decided to use it to > run my slow SCSI1 tape drives (an Archive Viper 150 and an Exabyte 8200). > I jumpered the 1542B to Interrupt 14 so as not to conflict with the 2940. > I don't know if this was necessary or not, but I did it anyway... I didn't > change anything else on the 1542B, including the DMA jumpers, which I > think are set to DMA 2 by default. (?) > > Anyway, now every time I try to access the tape drives, I get: > aha0: DMA beyond end of ISA: 0x19cc0a0 > st1: bad request, must be between 0 and 0 > tar: read error on /dev/rst1: Input/Output error > > I think perhaps I need to jumper the DMA to a different number, so I'm > going to try that now. But has anyone seen this before in a multi-SCSI > controller system? Any suggestions would be welcome. Thanks! Nope, read the message carefully. Your 1542 is trying to honor a DMA request at a memory address the ISA bus cannot reach: aha0: DMA beyond end of ISA: 0x19cc0a0 The ISA bus cannot address memory above 16M. You need to configure a new kernel with the BOUNCE_BUFFERS option, this will allow the 1542 driver to use a temporary buffer in ISA address space and then "bounce" the requests to the user program. -- "Where am I, and what am I doing in this handbasket?" Wes Peters Softweyr LLC http://www.xmission.com/~softweyr softweyr@xmission.com