Re: MSI messages

[Grant Grundler <grundler@parisc-linux.org>]

On Mon, Dec 15, 2008 at 04:07:53PM +0900, Kenji Kaneshige wrote:
> Grant Grundler wrote:
> >> To put it short: i am wondering how i should read the MSI messages.
> > 
> > The "message" is actually mapped to an the interrupt vector by the core
> > generic interrupt handling code in the kernel.
> > 
> > A "GSI" (Generic Sys Interrupt?) is associated with each entry in
> > the MSI-X table. Driver then calls request_irq() to bind an interrupt
> > handler to each GSI. So the driver never directly sees the "message".
> > 
> 
> I think "GSI (Global System Interrupt)" is for identifying the I/O
> APIC pin among multiple I/O APICs. Maybe you wanted to mean the
> interrupt number managed by kernel (frequently called "IRQ")?

I thought "GSI" and "kernel interrupt number" are equivalents.
But I could easily be confusing the terms here. If "GSI" is only
used for identifying APIC input lines, then that's not right term.

> Or am I misunderstanding something?

You probably understand it better than I do. :)

thanks,
grant