Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751292AbWB1KBb (ORCPT ); Tue, 28 Feb 2006 05:01:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751316AbWB1KBb (ORCPT ); Tue, 28 Feb 2006 05:01:31 -0500 Received: from jaguar.mkp.net ([192.139.46.146]:38100 "EHLO jaguar.mkp.net") by vger.kernel.org with ESMTP id S1751292AbWB1KBb (ORCPT ); Tue, 28 Feb 2006 05:01:31 -0500 To: "Bryan O'Sullivan" Cc: Andrew Morton , Andi Kleen , linux-kernel Subject: Re: [PATCH] Define wc_wmb, a write barrier for PCI write combining References: <1140841250.2587.33.camel@localhost.localdomain> From: Jes Sorensen Date: 28 Feb 2006 05:01:29 -0500 In-Reply-To: <1140841250.2587.33.camel@localhost.localdomain> Message-ID: User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.4 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 719 Lines: 16 >>>>> "Bryan" == Bryan O'Sullivan writes: Bryan> On some platforms, a regular wmb() is not sufficient to Bryan> guarantee that PCI writes have been flushed to the bus if write Bryan> combining is in effect. Bryan> This change introduces a new macro, wc_wmb(), that makes this Bryan> guarantee. Bryan, Could you explain why the current mmiowb() API won't suffice for this? It seems that this is basically trying to achieve the same thing. Cheers, Jes - 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/