Date: Wed, 4 Dec 1996 11:29:28 -0700 (MST) From: Softweyr LLC <softweyr@xmission.com> To: questions@freefall.freebsd.org Cc: mikebo@tellabs.com Subject: Re: 2.1.5R: aha0: DMA beyond end of ISA ? Message-ID: <199612041829.LAA27958@xmission.xmission.com> In-Reply-To: <199612041658.IAA00184@freefall.freebsd.org> from "owner-questions-digest@freefall.freebsd.org" at Dec 4, 96 08:58:50 am
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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
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