AW: 1 IRQ line for all bridged dev? RE: prob w/PCI add-in cards w/PCI 2PCI bridge on it

["Lange, Michael" <lange@dvs.de>]

-----Ursprüngliche Nachricht-----
Von: Lame Brooks-G14738 [mailto:Brooks_Lame@mcg.mot.com]
Gesendet am: Wednesday, October 13, 1999 9:47 PM
An: 'Lange, Michael'
Cc: 'PCISIGList'
Betreff: 1 IRQ line for all bridged dev? RE: prob w/PCI add-in cards
w/PCI 2PCI bridge on it



..snip..
> The best procedure for device selection is to use device 
> numbers 4,8 and
> 12 ( = data line 20,24 and 28) only
> in the case that only 1 IRQ line (INTA) should be shared by 
> all devices
> behind the bridge.
> /Michael

Why would you want to do that?  Is it just a personal preference for
intr
organization?  I suppose I could see doing that if all your devs behind
the
bridge were fixed and owned by one intr service routine.  -- BrooksL

....
There are hundreds of PC platforms worldwide which only support 1 IRQ
line (INTA) per PCI slot.
In the case that a PCI card with a bridge requests more than 1 IRQ
signal
(example : device 0 and 1 are used instead of 0 and 4) you will get
resource allocation problems

(driver under NT cannot be loaded or something like that).

Of course this is platform dependent. On SPARC-based Solaris computers
you can do whatever
you want with the 4 IRQ signals for each slot.

This is our experience we have made during the last 2 years.

/Michael