Message Signalled Interrupt support?

[Chuck Ebbert]

Jeff Garzik wrote:

> Has anybody done any work, or put any thought, into MSI support?
> 
> Would things massively break if I set up MSI manually in the driver?
> 
> I heard rumblings on lkml that Intel has done some work internally w/
> MSI support in Linux, but that doesn't help me much without further
> details ;-)

I found this in my archives:

================================

Subject: RE: [PATCH] 2.5.68 Fix IO_APIC IRQ assignment bug
Date: Mon, 21 Apr 2003 09:34:34 -0700
From: "Nakajima, Jun" <[e-mail]>

<SNIP>

After (vector-based)
           CPU0       CPU1       
  0:     709682          0    IO-APIC-edge  timer
  2:          0          0          XT-PIC  cascade
  9:          0          0   IO-APIC-level  acpi
 14:       4988          1    IO-APIC-edge  ide0
 15:         10          1    IO-APIC-edge  ide1
177:         78          0   IO-APIC-level  uhci-hcd
185:          0          0   IO-APIC-level  uhci-hcd, uhci-hcd
193:         58          0   IO-APIC-level  uhci-hcd
201:          0          0   IO-APIC-level  ehci-hcd
209:        356          0   IO-APIC-level  eth0
NMI:          0          0 
LOC:     707613     707524 
ERR:          0
MIS:          0

=========================================

  They changed things so the MSI scheme uses the vector number
directly instead of remapping it...