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Date: Fri, 26 Jan 2007 10:27:42 -0700
From: Grant Grundler <grundler@parisc-linux.org>
To: Segher Boessenkool <segher@kernel.crashing.org>
Subject: Re: [RFC/PATCH 0/16] Ops based MSI Implementation
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Cc: Grant Grundler <grundler@parisc-linux.org>,
	Greg Kroah-Hartman <greg@kroah.com>,
	Kyle McMartin <kyle@parisc-linux.org>, linuxppc-dev@ozlabs.org,
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On Fri, Jan 26, 2007 at 09:57:48AM +0100, Segher Boessenkool wrote:
> >>You code appears to be nice simple clean and to not support MSI in
> >>a useful way.  I may be reading too quickly but at the moment your
> >>infrastructure appears useless if you are on a platform that doesn't
> >>enforce MSI's get filtered with a legacy interrupt controller.
> >
> >Hrm?
> >Isn't the point of MSI to avoid any sort of interrupt controller?
> 
> No, the point of MSI is that it travels in the normal data
> stream (and stays ordered with it).  In the end it *has* to
> touch an interrupt controller (maybe the CPU-internal one).

Yes, sorry. I thinking about the properties of a "legacy interrupt
controller" and didn't intend that to mean the physical device:
    out-of-band delivery
    each IRQ line routed to one CPU on the motherboard,
    one IRQ line per device.

thanks,
grant