Subject: Re: port-i386/7807: 1.4 install floppy has "Bus-Master DMA error: missing interrupt" errs on install
To: Chris G. Demetriou <>
From: Manuel Bouyer <>
List: netbsd-bugs
Date: 06/24/1999 16:25:06
On Wed, Jun 23, 1999 at 04:26:30PM -0700, Chris G. Demetriou wrote:
> While this may be true, i'm hesitant to believe it.
> The system in question is an effectively-new Digital box (effectively
> because it was brand new but out of date when i bought it > a year
> ago, and it's spent most of its time turned off), with the stock
> from-factory hardware configuration except for the addition of the PCI
> ethernet card.

I've seen this on brand new hardware as well.

> >A too long cable, or with the wrong
> >impedence can be the cause of this. Can you try to use another
> >cable.
> I can't easily since I only own three and the other two are in use
> (and one's the identical twin to this one.)
> However, given that the machine is effectively-new and the cable is
> the one shipped from the factory (i've never even unplugged it!), and
> they presumably do QA on their hardware, i'd expect it to perform
> properly.  Anyway, if I get a chance, i'll try to get another IDE cable.

Did they test DMA ? I'm not sure there was an OS supporting DMA at the
time, and I think for the moment we are the only OS using it by default.

I don't say there isn't a problem in the driver, but each time I've seen it
I could find hardware parameter that could change the behavior (and some time
just changing the IDE cable is enouth).

Manuel Bouyer, LIP6, Universite Paris VI.