Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265848AbUAHRnt (ORCPT ); Thu, 8 Jan 2004 12:43:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265784AbUAHRlr (ORCPT ); Thu, 8 Jan 2004 12:41:47 -0500 Received: from mtvcafw.SGI.COM ([192.48.171.6]:251 "EHLO zok.sgi.com") by vger.kernel.org with ESMTP id S265806AbUAHRkC (ORCPT ); Thu, 8 Jan 2004 12:40:02 -0500 Date: Thu, 8 Jan 2004 09:39:49 -0800 To: Leonid Grossman Cc: "'Grant Grundler'" , linux-kernel@vger.kernel.org, jeremy@sgi.com, "'Matthew Wilcox'" , linux-pci@atrey.karlin.mff.cuni.cz, Jame.Bottomley@steeleye.com Subject: Re: [RFC] Relaxed PIO read vs. DMA write ordering Message-ID: <20040108173949.GB11168@sgi.com> Mail-Followup-To: Leonid Grossman , 'Grant Grundler' , linux-kernel@vger.kernel.org, jeremy@sgi.com, 'Matthew Wilcox' , linux-pci@atrey.karlin.mff.cuni.cz, Jame.Bottomley@steeleye.com References: <20040108063829.GC22317@colo.lackof.org> <005b01c3d603$d01b6c90$0400a8c0@S2IOtech.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <005b01c3d603$d01b6c90$0400a8c0@S2IOtech.com> User-Agent: Mutt/1.5.4i From: jbarnes@sgi.com (Jesse Barnes) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1023 Lines: 24 On Thu, Jan 08, 2004 at 08:23:49AM -0800, Leonid Grossman wrote: > > I interpret this to mean: > > Setting the RO bit in the PCI-X Command Register only enables > > the device to choose when to set RO Attribute bit when the device > > generates a PCI-X bus cycle. > > Yes, this is exactly how (at least our 10GbE) PCI-X ASICs work. > If the RO bit is set, the device decides whether the transaction > requires strong ordering, > and sets RO attribute accordingly. Excellent, a card in the wild that actually does this! :) Ok, now I'll take of my sn2 tunnel vision glasses--we don't want another readX variant, but it sounds like we'll need pcix_enable_relaxed() _and_ pci_sync_consistent() to support non-coherent platforms well. How does that sound? Thanks, Jesse - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/