Messages in this thread | | | Date | Tue, 4 Mar 2003 18:36:26 -0500 (EST) | From | Donald Becker <> | Subject | Re: PCI init issues |
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On Wed, 5 Mar 2003, Ivan Kokshaysky wrote:
> On Tue, Mar 04, 2003 at 01:16:22PM -0500, Donald Becker wrote: > > Incorrect. > > Most quad Tulip boards have the bus bridge wired so that all interrupts > > are sent on the INTA output of the board. > > This can be true for older cards, but post-1998 hardware must follow > the spec. > PCI-to-PCI Bridge Architecture Specification, Rev 1.1, Dec 18, 1998,
The reality is that most quad Tulip boards were designed before 1999, and therefore act as I described.
Most of the experience is with quad Ethernet adapters, as there are few other common PCI boards with bus bridges.
> I know for a fact that at least D-Link card mentioned in some reports > utilizes all four INT# lines, because I have one.
The D-Link board is
> Device 0 on a secondary bus will have its INTA# line connected to > the INTA# line of the connector. Device 1 will have its INTA# line > connected to INTB# of the connector. This sequence continues and > then wraps around once INTD# has been assigned."
This seems to be what most x86 BIOSes assume (almost all BIOSes use the Intel reference code for PCI setup), even from 1995-era machines. But again, this does not match how _most_ of the quad boards are wired. Curiously, non-x86 machines usually work fine without the work-around, meaning that they have a different interpretation.
-- Donald Becker becker@scyld.com Scyld Computing Corporation http://www.scyld.com 410 Severn Ave. Suite 210 Scyld Beowulf cluster system Annapolis MD 21403 410-990-9993
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