Subject: Re: No IDE-DMA after sup today ("no driver support")...
To: Guenther Grau <>
From: Perry E. Metzger <>
List: current-users
Date: 10/21/1998 11:47:42
Guenther Grau writes:
> > This was with a PIIX4. Maybe some other controllers have a more fair
> > behavior. But I think it's better to say "your disk is used in PIO
> > mode because the pciide driver doesn't support your controller" than
> > "your machine hang when you try to install NetBSD on it because
> > the pciide driver doesn't support your controller".
> I agree with you! However, wouldn't it be possible to to have a
> config option to enable DMA anyways? This would be turned off
> by default. If the user is running NetBSD and wants to try the benefits
> of DMA, he might just try to turn this option on and see what
> happens on his computer. The implications of this option should 
> be clearly marked. Doing this wouldn't impose any limits on the
> users, but I don't know if this is possible with the code you
> wrote.

This would be really good. Then most of us could try to use DMA and if 
it failed, we could always back out.