Date: Wed, 20 Mar 2002 03:15:42 -0800 (PST)
From: Andre Hedrick <andre@linux-ide.org>
To: Martin Dalecki <dalecki@evision-ventures.com>
cc: Dan Hopper <ku4nf@austin.rr.com>, linux-kernel@vger.kernel.org
Subject: Re: Promise 20265 IDE chip gets detected in wrong order 2.4.x
In-Reply-To: <3C986533.3000008@evision-ventures.com>
Message-ID: <Pine.LNX.4.10.10203200243010.525-100000@master.linux-ide.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Sender: linux-kernel-owner@vger.kernel.org


Hi Martin,

You kind of missed a few points and issues, so I would like to offer you
some help.

This is easily address by applying the exclusive rule of the seeking the
SouthBridge device.  Once this is found, one generally assumes this to be
the PCI_BASE_CLASS_BRIDGE + PCI_CLASS_BRIDGE_ISA or 601h.  It will
(should future unknown) have  a function number of 0 "zero".  Once the
location of the SB has been determined one seeks for function 1 "one".
Once SB + func 1 is found, tests for device class PCI_BASE_CLASS_STORAGE +
PCI_CLASS_STORAGE_IDE or 101h.

Unless otherwise specifed this shall always be the INT13 device; however,
one does not exclude SCSI/RAID or any other device class having rights to
INT13 hooks.  Since linux does not support these type of BIOS services the
fore mentioned is the preferred ruleset.

This would have been applied to 2.5 but you are now free to do so
yourself.  As for all other booting devices under INT19 calls to load
option roms, which in the past have been considered valid, permit
ATA-HBA's to gain access to the priviledge hwgroup pair ide0/ide1.

This is all a design of detection ordering to override the nasty tricks
played by chipset venders attempting to do have their secondary host or
hba to be the preferred hardware to use.

The history of this problem is a result of HBA's coming to market before
system chipset.  Also people who have very good and useful systems who
want to boost their storage performance tend to drift to the HBA world.
Others who load the system up with every toy in the market place run out
of interrupts early (past w/ ISA physical slots), they find it useful and
practical to disable the legacy host to gain back an additional interrupt
but not loose the total storage device count before the addition of the
HBA.

Cheers,

Andre Hedrick
LAD Storage Consulting Group

On Wed, 20 Mar 2002, Martin Dalecki wrote:

> Dan Hopper wrote:
> > Andre Hedrick <andre@linux-ide.org> remarked:
> > 
> >>append="ide=reverse"
> > 
> > 
> > You're right, this works, too, and is a lot easier to remember than
> > the override I used before.  
> > 
> > 
> >>Various Mainboard manufacturers do things to place the FAKE-RAID in front
> >>of the the legacy south bridge.  This is classic Windows spoofing.
> >>
> >>
> >>>PDC20265: IDE controller on PCI bus 00 dev 68
> >>>VP_IDE: IDE controller on PCI bus 00 dev 89
> >>
> > 
> > So, the I/O port assignments don't in fact properly determine the
> > assignment order?  I'm gathering from what you're saying that the
> > current behavior is related to PCI bus location?
> 
> Precisely: The PCI bus detection order matters.
> 

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/