Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 17 Jan 1997 01:36:34 -0500 (EST)
From:      Kenneth Merry <ken@housing1.stucen.gatech.edu>
To:        smp@csn.net (Steve Passe)
Cc:        smp@freebsd.org
Subject:   Re: Adaptec 3940UW and SMP
Message-ID:  <199701170636.BAA22619@housing1.stucen.gatech.edu>
In-Reply-To: <199701170549.WAA15160@clem.systemsix.com> from Steve Passe at "Jan 16, 97 10:49:18 pm"

next in thread | previous in thread | raw e-mail | index | archive | help
Steve Passe wrote...

> > 	Indeed, that works.  So now things look like this:
> > 
> > Slot 1: Adaptec 3940UW   (IRQ 11)
> > Slot 2: Matrox Millenium (IRQ 10)
> > Slot 3: Empty            (IRQ 9)
> > Slot 4: SMC 10/100 card  (IRQ 15)
> > Slot 5: Empty            (shares IRQ w/ slot 4)
> > 
> > 	ahc1 now grabs IRQ 10 from the millenium, and things seem to work
> > okay.  This will hopefully enable me to add a video capture card at least,
> > and perhaps a second ethernet card.  :)

> could you expand on the comment "(shares IRQ w/ slot 4)"?  I visited the
> ASUS site an noticed that there were 5 (NOT 4) slots on this board and thought
> perhaps that that was done by making 2 PCI busses on the motherboard proper.
> Thus I wasn't sure if you were seeing PCI0 and PCI1 because of this fact, or
> because the BIOS was smart enough to see the PCI bridge on the 3940.
> Since both ahc and ed0 are in the 1st 4 slots, and presumably the
> MP table/dmesg shows them on pci1 and pci0, respectively, it appears to be
> the result of a BIOS 'doing the good thing'!  This is re-enforced by the
> MP table for the same ASUS board owned by someone else that has no
> bridge cards and shows only 1 PCI bus (MP table database entry #5).

	Well, the manual isn't very revealing about whether there are
actually one or two PCI busses on the board.  The 5th slot is a a "shared"
PCI/ISA slot, and it also has an ASUS MediaBus connector in line with the
PCI connector.  Here's what the board manual says about slot 5 and
interrupts:

"IMPORTANT: PCI Slots 4 & 5 share the same IRQ.  If using PCI cards on both
slots 4 & 5, make sure taht the drivers support "Share IRQ" or that one
card does not need an IRQ assignment.  Conflicts will arise on PCI Slots 4
& 5 taht will make the system unstable."

	In the bios, you can hardwire the interrupt for slots 1, 2, 3 by
themselves.  Slots 4 and 5 are lumped together, one IRQ for both.  This
probably isn't news, but just in case it is, in the C-P6ND (cpu
daughtercard) manual, it says:  

"All PCI bus slots on the system use INTA#, thus all installed cards must
be set to this value."

	That comment is in the section that talks about the bios interrupt
assignment stuff.  So, based on what you said, and the fact that it doesn't
assign another IRQ to that slot, I'd bet that they just tacked on another
slot, and didn't put a bridge chip on the board.  (just a guess, I could be
wrong of course. :) )

	If it'll help, I can always look around the boards for bridge
chips. :)  


Ken
-- 
Kenneth Merry
ken@ulc199.residence.gatech.edu
Disclaimer:  I don't speak for GTRI, GT, or Elvis.



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199701170636.BAA22619>