Subject: Re: Handling orphans in config(1)
To: der Mouse <mouse@Rodents.Montreal.QC.CA>
From: Quentin Garnier <cube@cubidou.net>
List: tech-kern
Date: 09/28/2005 11:32:03
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On Wed, Sep 28, 2005 at 04:56:16AM -0400, der Mouse wrote:
> >>       parent* at wherever
> >>       child0 at parent0
> >>       child* at parent1
>=20
> > The last one isn't really acceptable, as instances of the parent
> > device may suddenly be probed in another order, thus changing the
> > identity of child0 and its siblings.
>=20
> So?  "You asked for it, you got it."  It makes sense to me to say "I
> don't care which of these is parent0, but I want child0 to be the one
> attached to parent0, whichever one that is".  It's hard to see a use
> for this in most cases, because most things that can be attached to
> don't have interfaces of their own, but if both parent and child can be
> open()ed or otherwise manipulated in their own right, getting things
> paired up correctly can be important.
>=20
> The only case I can think of offhand where this could actually be
> useful would be some kind of hardware resource that is accessible only
> to software - no external hardware interface.  Take a crypto
> accelerator, for example, which can provide AES, DES, and/or Blowfish
> support (yes, I know this is not how crypto accelerators are actually
> done):
>=20
> 	crypto* at wherever
> 	aes0 at crypto0
> 	des0 at crypto0
> 	blowfish0 at crypto0
> 	aes* at crypto?
> 	des* at crypto?
> 	blowfish* at crypto?

I really wonder what is so wrong about being explicit.  Having the
following is perfectly fine, and just seems like the thing to do to me:

        crypto0 at whatever
        crypto* at whatever

My point is just that if you want something to explicitly attach to
crypto0, you should have an explicit crypto0 device.

--=20
Quentin Garnier - cube@cubidou.net - cube@NetBSD.org
"When I find the controls, I'll go where I like, I'll know where I want
to be, but maybe for now I'll stay right here on a silent sea."
KT Tunstall, Silent Sea, Eye to the Telescope, 2004.

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