Date: Wed, 8 Jan 1997 15:27:44 -0500 From: "Steve Sims" <SimsS@IBM.Net> To: "Terry Lambert" <terry@lambert.org> Cc: <terry@lambert.org>, <Hackers@FreeBSD.ORG> Subject: Re: Bounce Buffers and CCD Message-ID: <199701082041.UAA123445@smtp-gw01.ny.us.ibm.net>
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> From: Terry Lambert <terry@lambert.org> > > >> (Terry, I hope I haven't quoted you out of context, but I'm here to tell > > >> ya': BOUNCE-BUFFERS is a MANDATORY option for >16M systems, at least on > > >> 3.0-CURRENT with my mo-bo having PCI, ISA and VESA!) > > > > > > Then it's not required AND it's broken. 8-(. > > > > > > Bounce conditions are supposed to be autodetected. > > > > Would that it were true.... > > > Bounce buffers should be implied by the 1542 driver, automagically. If > they are not, then the driver is broken; I would guess "recently". Settled: The driver looks to be broken. I'll sup -CURRENT and see if it's been magically fixed, if not, how to proceed with tracking this down; who's the keeper of the 1542 code? > It's not PCI/VESA, so it's 24 (standard for ISA). Means the DMA target > has to be in the low 16M, and if it isn't it needs to be "bounced". > This is determined by knowing that it's an AHA1542 driver (ISA DMA > bus master) and comparing the address to see if it's above 16M. > > > "Supposed" being the operative term here... ;-) > > "Is handled as far as I know for non-broken hardware that meets the > bus specifications as ratified as accepted standards". > > In other words, making NiCE HiNT chipset machines work is out of scope > (but possible -- see previous postings for this subject). I shudder at the recollection of *that* brain-damaged chipset! ...sjs...
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