Date: Fri, 29 May 1998 09:54:19 +0930 From: Greg Lehey <grog@lemis.com> To: Matthew Thyer <Matthew.Thyer@dsto.defence.gov.au> Cc: Karl Pielorz <kpielorz@caladan.tdx.co.uk>, current@FreeBSD.ORG Subject: Re: aha1542 - again... Message-ID: <19980529095419.G25469@freebie.lemis.com> In-Reply-To: <356DF05A.E4B3AE09@dsto.defence.gov.au>; from Matthew Thyer on Fri, May 29, 1998 at 08:46:42AM %2B0930 References: <Pine.BSF.3.96.980528000408.626A-100000@caladan.tdx.co.uk> <19980528123712.H4179@freebie.lemis.com> <356DF05A.E4B3AE09@dsto.defence.gov.au>
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On Fri, 29 May 1998 at 8:46:42 +0930, Matthew Thyer wrote: > Greg Lehey wrote: >> >> On Thu, 28 May 1998 at 0:07:15 +0100, Karl Pielorz wrote: >>> >>> I read a while ago there were problems with the existing AHA1542 support >>> on -current... I also read that someone (I can't remember now who it was) >>> said they'd been through the code and fixed up a few things... >>> >>> As I remember it was a problem to do with bounce buffers... >>> >>> I've just had to add a 1542CF to my machine (as I'm out PCI slots and it >>> was 'hanging around'), and I've run into problems with it - but I'm not >>> sure there to do with bounce buffers etc. >>> >>> I know CAM is looking almost 'immanent' - but can anyone confirm whether >>> the 1542 driver is in any useable state in -current at the moment? >> >> I'm developing vinum on a -CURRENT machine with a 1542B. I had >> trouble with a 1542A, which appears to be a known problem (a number 0f >> 0xff bytes strewn at regular intervals, usually 32K), but the 1542B is >> working fine. >> >>> I have 2 x Double-Speed CD-ROM drives hooked up to it, I wouldn't have >>> thought they were particularly 'stressy' for the driver ;-) >> >> Do you have problems? You'll need bounce buffers for any ISA DMA >> device if you have more than 16 MB memory. > > I am about to add a 1542B to my current system and want to know about > the bounce buffer issue. > > How do I tell whether the device I'm adding does DMA ? I suppose the safest way is to read the technical documentation. Failing that, the driver documentation may tell you. > Do the probe messages tell me ? Sometimes. Don't rely on it. > It's an ISA card and its an Adaptec 1542B so I assume being a SCSI card > it will do DMA Just because it's a SCSI board doesn't mean it does DMA. The fact that it's a 1542 does mean it'll do DMA, however. The 1520 doesn't, as far as I can recall. > so I suppose I should include BOUNCE_BUFFERS since I have 32MB RAM > on this P100. Correct. I think the system complains if you don't. Greg -- See complete headers for address and phone numbers finger grog@lemis.com for PGP public key To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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