Date: Thu, 2 Dec 1999 11:34:45 -0700 (MST) From: "Kenneth D. Merry" <ken@kdm.org> To: mjacob@feral.com Cc: syssgm@detir.qld.gov.au (Stephen McKay), freebsd-scsi@FreeBSD.ORG Subject: Re: Tape driver problems Message-ID: <199912021834.LAA50772@panzer.kdm.org> In-Reply-To: <Pine.BSF.4.05.9912021019270.369-100000@semuta.feral.com> from Matthew Jacob at "Dec 2, 1999 10:20:19 am"
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Matthew Jacob wrote... > > > > > This is an "old" problem, ie more than 2 weeks, at least. :-) > > > > > > > > "mt status" with a tape loaded gives the correct values (including density), > > > > but the kernel spits out: > > > > > > > > Dec 3 00:44:36 bucket /kernel: bus_dmamap_load: Too many segs! buf_len = 0x3000 > > > > > > > > The last bit changes. I've seen 0xb000 or 0xd000 or 0xe000 or 0xf000 also. > > > > This is a new problem related to the density autodetection read. I expect > > > > that an aha1542B just can't read MAXPHYS bytes from anything. > > > > > > Hmm, indeed. The density determining code does indeed issue a read of > > > MAXPHYS bytes. It seems to me that all HBA's should at least support that! > > > The maintainer for the 1542X will have to speak to this tho... > > > > I'm not the aha maintainer (Warner is), but I do know that it cannot do > > I didn't say you were. I know you didn't. But if I didn't make that qualification, from previous experience I can guess that I would get mail from a few people complaining about some problem they have with their aha board. I was just trying to take some preventative action. > > more than 64K at a time. So you shouldn't be using any more than that. > > Nonsense. That's what bounce buffers can or *should* be used for too. Well, talk to Warner about it. You could probably use bounce buffers to handle the problem. For now, though, I think 64K is the lowest common denominator. Ken -- Kenneth Merry ken@kdm.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message
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