Subject: Re: Support for controllers without aux registers in MI wdc
To: Manuel Bouyer <>
From: Ilpo Ruotsalainen <>
List: tech-kern
Date: 01/14/2003 00:41:47
On Mon Jan 13 2003 at 23:17:48 +0100, Manuel Bouyer wrote:
> On Mon, Jan 13, 2003 at 10:57:50PM +0200, Ilpo Ruotsalainen wrote:
> > Attached is a patch to add a flag so the MI wdc can handle controllers
> > that lack aux registers (needed for my amiga IDE-doubler work). Could
> > someone check that this is ok before I commit, please.
> Are you sure it can't be resetted at all ?
> Some other controllers have no aux registers, but have an extended command
> register to do it (e.g. atari/dev/wdc_mb.c I think, or mac68k/obio/wdc_obio.c)
> reset is almost a requirement for a working IDE controller :)

Well, people who use these pieces of horror under AmigaOS say 'since it
cannot be reset, if you get a bus hang you have to hard reboot' so I'm
kinda inclined to trust them. Besides, this is *not* a true feature of
the controller but a hack to add a feature it doesn't really have at the
cost of losing the reset ability. (Without an IDE doubler the controller
has aux registers and resets just fine.)

It 'kinda works' without the reset as long as you don't get a bus hang
or some other situation from which reset is the only way out.

Ilpo Ruotsalainen - <> -