Re: autoconf question

[Paul Goyette <paul%whooppee.com@localhost>]

On Fri, 4 Jul 2008, Quentin Garnier wrote:

> > That's what the attach args (aux) are for.  Have the parent enough
>
> That and the interface attribute (the ia in the API).  If there are
> two classes of child devices, that begs for different interface
> attributes.  Please don't abuse the attach args for that.

Hmmm.  Based on the docs available, I was under the impression that 
interface attributes were for the child to be able to attach to 
different parents.  Such as the ld(4) driver attaching to all sorts of 
RAID controllers.  In fact, one of the children of my driver is yet 
another (non-RAID) interface for ld.

So what I've got is

        device  sdhc: sdmmcbus
        attach  sdhc at pci with sdhc_pci
        file . . . .

        device  sdmmc { }
        attach  sdmmc at sdmmcbus
        file . . . .

        attach ld at sdmmc with ld_sdmmc
        file .../ld_sdmmc.c

        device flashcard at sdmmc
        file ...

When an instance of sdmmc attaches to the sdmmcbus (ie, a card is 
inserted), I want to attach an ld and a card-specific I/O driver for 
each "function" offered by the card.  The configuration process seems 
only to evaluate the match of all possible children and picks the best 
one.

Since I need to have _two_ children, I can run config_match*() twice, 
but I need to have the ld driver get selected the first time, and the 
other driver selected on the second call.

I suppose I could make use of a pseudo-locator but that seems to me to 
be at least as ugly as passing a dont't-let-ld-match value in the 
attach_args.

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