From owner-freebsd-current@FreeBSD.ORG Mon Apr 11 15:46:10 2005 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 9541B16A4CE for ; Mon, 11 Apr 2005 15:46:10 +0000 (GMT) Received: from duke.cs.duke.edu (duke.cs.duke.edu [152.3.140.1]) by mx1.FreeBSD.org (Postfix) with ESMTP id C571343D45 for ; Mon, 11 Apr 2005 15:46:09 +0000 (GMT) (envelope-from gallatin@cs.duke.edu) Received: from grasshopper.cs.duke.edu (grasshopper.cs.duke.edu [152.3.145.30]) by duke.cs.duke.edu (8.13.1/8.13.1) with ESMTP id j3BFk3bj017349 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Mon, 11 Apr 2005 11:46:03 -0400 (EDT) Received: (from gallatin@localhost) by grasshopper.cs.duke.edu (8.12.9p2/8.12.9/Submit) id j3BFjlkG002518; Mon, 11 Apr 2005 11:45:47 -0400 (EDT) (envelope-from gallatin) From: Andrew Gallatin MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <16986.39851.597421.478406@grasshopper.cs.duke.edu> Date: Mon, 11 Apr 2005 11:45:47 -0400 (EDT) To: Scott Long In-Reply-To: <425A10DD.70500@samsco.org> References: <20050406233405.O47071@carver.gumbysoft.com> <200504081656.51917.jhb@FreeBSD.org> <20050410152946.W82708@carver.gumbysoft.com> <20050410172818.D82708@carver.gumbysoft.com> <200504110231.j3B2VOYr047361@apollo.backplane.com> <425A10DD.70500@samsco.org> X-Mailer: VM 6.75 under 21.1 (patch 12) "Channel Islands" XEmacs Lucid cc: freebsd-current@freebsd.org Subject: Re: Potential source of interrupt aliasing X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 11 Apr 2005 15:46:10 -0000 Scott Long writes: > > See also: sbus(4), msi(4). > > MSI is something that I'd like to work on, but simply had the time. > It's not a panacea since it will only work for MSI-enabled PCI devices, > but many peripherals found on these Intel systems fall into that > category. Bear in mind that MSI is another can of worms. I spent some time last month getting MSI interrupts working for our linux driver. I had the misfortune to start with a system (ServerWorks GC-SL based) which did not even support MSIs, but where linux let my driver enable MSI operation and allocate MSI interrupts. Any DMA to the address given by the linux MSI code resulted in a PCI master abort. That was not fun.. If/when we do MSI support, I really hope we do a better job of determining if MSIs actually work before enabling them ;) Drew