Subject: Re: ed device with bus.h failes to clear shared memory
To: Jason Thorpe <thorpej@nas.nasa.gov>
From: Justin T. Gibbs <gibbs@freefall.freebsd.org>
List: current-users
Date: 05/03/1996 21:34:04
>On Fri, 03 May 1996 10:59:59 -0700 
> "Michael L. VanLoon -- HeadCandy.com" <michaelv@HeadCandy.com> wrote:
>
> > >> bt0 at isa0 port 0x330-0x333 irq 11: model BT-747, firmware 3.37
> > 
> > >Uhmm??           :)  (yeah, I know what a 747 is..)
> > 
> > Well, unlike the 1742, the BT747 uses the "universal" bt driver, which
> > uses the same interface for all cards (and bus types), and hasn't yet
> > been broken out into bus-specific drivers.
>
>...mostly because the current driver doesn't yet support turning off the 
>ISA re-mapping on the EISA cards.

You can't disable the "ISA" port address on the EISA Buslogic adapters.  In
fact you have no choice but to access the card through this lower port
address.  What you can do, is non-invasively determine what the "ISA" port
address is for the card by looking in slot space for it.  This is what the
FreeBSD EISA probe for Buslogic cards does.  Because FreeBSD lacks a
generic resource reservation/conflict detection mechanism that spans bus
types, the driver does its own (hack, hack) checking when looking for ISA
cards to see if an EISA card has already claimed that address.

You can disable the "ISA compatibility" address on the newer versions of
the PCI adapters though this is a different issue since on those cards
you can either access them through the higher PCI address or the lower
"ISA compatibility" address.

>----save the ancient forests - http://www.bayarea.net/~thorpej/forest/----
>Jason R. Thorpe                                       thorpej@nas.nasa.gov
>NASA Ames Research Center                               Home: 408.866.1912
>NAS: M/S 258-6                                          Work: 415.604.0935
>Moffett Field, CA 94035                                Pager: 415.428.6939

--
Justin T. Gibbs
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