Subject: Re: needs MI wdc changes to support macppc's wdc
To: Jason Thorpe <thorpej@nas.nasa.gov>
From: Ignatios Souvatzis <ignatios@theory.cs.uni-bonn.de>
List: tech-kern
Date: 11/04/1998 10:30:37
On Tue, Nov 03, 1998 at 11:15:09AM -0800, Jason Thorpe wrote:
> On Wed, 4 Nov 1998 01:04:06 +0900 (JST) 
>  tsutsui@ceres.dti.ne.jp (Izumi Tsutsui) wrote:
> 
>  > I think it is better to use offset array to access wdc register,
>  > though it would make some overheads on archs which have only contiguous
>  > addressed wdc (like i386).
>  > 
>  > Any suggestions?
> 
> I don't think it will be much overhead.  For multi-pio, the address will
> be computed only once.  I think the reg map in the wdc driver is the right
> way to go.

Yes, but ports as the Amiga that need variable strides in bus_space anyway
will get the double overhead.

	-is