Date: Wed, 17 Dec 2008 22:47:19 -0700
From: Grant Grundler <grundler@parisc-linux.org>
To: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Cc: Grant Grundler <grundler@parisc-linux.org>,
        Manu Abraham <abraham.manu@gmail.com>, linux-kernel@vger.kernel.org,
        linux-pci@vger.kernel.org
Subject: Re: MSI messages
Message-ID: <20081218054719.GA10633@colo.lackof.org>
References: <49438290.1080502@gmail.com> <20081214081210.GC13371@colo.lackof.org> <49460249.8020801@jp.fujitsu.com>
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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
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