Subject: Re: DMA wdc* on VL-Bus controller?
To: Todd Vierling <tv@NetBSD.ORG>
From: John F. Woods <>
List: port-i386
Date: 12/09/1997 13:17:00
> Hrm, I've got this here VL-Bus IDE/IO controller card, and a spiffy ol'
> VL-Bus 486DX motherboard with three of them there VL slots.
> so I went on and added "drq 3" to the wdc0 line in my
> config.  The box boots, shows wdc0 as DMA, but when the durn thing gets to
> doin' the root disk selection, it hangs and is only givin' me a repeated
> timeout of "lost IRQ."
> So:  is DMA actually sup'ported on this here board, or on IDE in general?

The VL-bus "standard" (such as it is) specifies a two-slot maximum, so some
liberties are likely to have been taken on that motherboard.  (Another 
popular liberty, which afflicts my MB, is not to wire up all the address lines,
which results in an instant hard reboot if I try an X server with linear
address mapping (for instance).)

But there could be more specific software problems getting in your way.