From: "David S. Miller" <davem@davemloft.net>
To: gregkh@suse.de
Cc: tom.l.nguyen@intel.com, linux-pci@atrey.karlin.mff.cuni.cz,
linux-kernel@vger.kernel.org, roland@topspin.com
Subject: Re: pci_enable_msi() for everyone?
Date: Mon, 06 Jun 2005 15:59:54 -0700 (PDT) [thread overview]
Message-ID: <20050606.155954.59466251.davem@davemloft.net> (raw)
In-Reply-To: <20050606225548.GA11184@suse.de>
From: Greg KH <gregkh@suse.de>
Date: Mon, 6 Jun 2005 15:55:49 -0700
> Why would it matter? The driver shouldn't care if the interrupts come
> in via the standard interrupt way, or through MSI, right? And if it
> does, it could always use a function like the one I proposed to set up a
> different irq handler.
It matters because MSI totally changes the DMA vs. interrupt delivery
guarentees.
With MSI, you can be assured that any DMA sent from the device, before
the interrupt, has reached global visibility before the MSI arrives at
the cpu. There is no such guarentee with pre-MSI interrupt delivery.
Drivers optimize this, so they have to know if MSI is being used or
not.
next prev parent reply other threads:[~2005-06-06 23:33 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-06-03 22:45 Greg KH
2005-06-03 23:16 ` Jeff Garzik
2005-06-04 0:01 ` Benjamin Herrenschmidt
2005-06-04 0:08 ` Jeff Garzik
2005-06-04 0:16 ` Benjamin Herrenschmidt
2005-06-04 0:34 ` Jeff Garzik
2005-06-04 6:51 ` Greg KH
2005-06-03 23:36 ` Roland Dreier
2005-06-06 22:58 ` Greg KH
2005-06-07 0:23 ` Roland Dreier
2005-06-07 5:19 ` Greg KH
2005-06-04 1:31 ` Grant Grundler
2005-06-04 6:48 ` Greg KH
2005-06-04 7:05 ` Grant Grundler
2005-06-04 7:18 ` Greg KH
2005-06-04 7:23 ` Dave Jones
2005-06-04 14:58 ` Roland Dreier
2005-06-06 23:01 ` Greg KH
2005-06-07 0:26 ` Roland Dreier
2005-06-07 5:22 ` Greg KH
2005-06-07 5:46 ` Adam Belay
2005-06-07 17:43 ` Luben Tuikov
2005-06-05 22:00 ` Benjamin Herrenschmidt
2005-06-06 23:00 ` Greg KH
2005-06-06 23:56 ` Benjamin Herrenschmidt
2005-06-05 19:46 ` David S. Miller
2005-06-06 22:55 ` Greg KH
2005-06-06 22:59 ` David S. Miller [this message]
2005-06-06 23:09 ` Greg KH
2005-06-06 23:08 ` Jeff Garzik
2005-06-06 23:10 ` David S. Miller
2005-06-06 23:13 ` Greg KH
2005-06-06 23:53 ` Jeff Garzik
2005-06-06 23:56 ` Greg KH
2005-06-06 23:58 ` David S. Miller
2005-06-07 4:24 ` Grant Grundler
2005-06-07 0:18 ` Roland Dreier
2005-06-07 5:21 ` Greg KH
2005-06-07 22:33 Nguyen, Tom L
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20050606.155954.59466251.davem@davemloft.net \
--to=davem@davemloft.net \
--cc=gregkh@suse.de \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pci@atrey.karlin.mff.cuni.cz \
--cc=roland@topspin.com \
--cc=tom.l.nguyen@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®