From: "Mika Penttilä" <mika.penttila@kolumbus.fi>
To: "David S. Miller" <davem@redhat.com>
Cc: willy@debian.org, jgarzik@pobox.com,
linux-kernel@vger.kernel.org, ink@jurassic.park.msu.ru
Subject: Re: Message Signalled Interrupt support?
Date: Mon, 12 May 2003 21:54:09 +0300 [thread overview]
Message-ID: <3EBFEDD1.2060904@kolumbus.fi> (raw)
In-Reply-To: 20030512.102023.71099561.davem@redhat.com
I think that MSI should be made quite explicit. If the device and
platform both support MSI, then the driver should be able to ask for
MSI, but kernel must be able to deny it. All devices supporting MSI must
support also pin based interrupt delivery. As MSI can be costy (one
interrupt vector per device for instance), it could be that a device has
to work in pin based mode instead.
--Mika
David S. Miller wrote:
> From: Matthew Wilcox <willy@debian.org>
> Date: Mon, 12 May 2003 17:53:31 +0100
>
> On Mon, May 12, 2003 at 12:32:49PM -0400, Jeff Garzik wrote:
> > Has anybody done any work, or put any thought, into MSI support?
>
> Work -- no. Thought? A little. Seems to me that MSIs need to be
> treated as a third form of interrupts (level/edge/message).
>
>The fact that Alpha already supports them pretty much transparently
>suggests that the thing to do might very well be "nothing" :-)
>
>To be honest, MSIs are very similar to how interrupts work on sparc64,
>in that each device generates a unique interrupt cookie. The only
>different is the size of this cookie, MSIs are larger than sparc64's.
>-
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>
next prev parent reply other threads:[~2003-05-12 18:35 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-05-12 16:32 Message Signalled Interrupt support? Jeff Garzik
2003-05-12 16:53 ` Matthew Wilcox
2003-05-12 17:20 ` David S. Miller
2003-05-12 18:54 ` Mika Penttilä [this message]
2003-05-12 17:43 ` Matt Porter
2003-05-12 18:20 ` Matthew Wilcox
2003-05-12 18:48 ` Matt Porter
2003-05-13 11:21 ` Ivan Kokshaysky
2003-05-12 17:26 Chuck Ebbert
2003-05-12 17:53 Nakajima, Jun
2003-05-12 18:26 Nakajima, Jun
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