Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754586AbYJLHjW (ORCPT ); Sun, 12 Oct 2008 03:39:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751234AbYJLHjN (ORCPT ); Sun, 12 Oct 2008 03:39:13 -0400 Received: from colo.lackof.org ([198.49.126.79]:34885 "EHLO colo.lackof.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751035AbYJLHjL (ORCPT ); Sun, 12 Oct 2008 03:39:11 -0400 Date: Sun, 12 Oct 2008 01:38:59 -0600 From: Grant Grundler To: Roland Dreier Cc: Matthew Wilcox , Yinghai Lu , Andrew Morton , Jesse Barnes , FUJITA Tomonori , grundler@parisc-linux.org, mingo@elte.hu, tglx@linutronix.de, hpa@zytor.com, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org Subject: Re: [PATCH] pci: print out DMA mask info Message-ID: <20081012073859.GE20056@colo.lackof.org> References: <1223506943-6543-1-git-send-email-yinghai@kernel.org> <20081009211837.GC18444@colo.lackof.org> <20081010114002D.fujita.tomonori@lab.ntt.co.jp> <200810100848.09557.jbarnes@virtuousgeek.org> <86802c440810100919xf79f406x403988da7988edc9@mail.gmail.com> <20081010163350.GF25780@parisc-linux.org> <48EF86E9.8030408@kernel.org> <20081010171214.GG25780@parisc-linux.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Home-Page: http://www.parisc-linux.org/ User-Agent: Mutt/1.5.16 (2007-06-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1131 Lines: 30 On Fri, Oct 10, 2008 at 10:18:33AM -0700, Roland Dreier wrote: > > Open-coding DMA_BIT_MASK() within your driver means that we no longer > > have a canonical list of DMA masks in one place. Instead we have to > > grep the entire tree and come up with more-or-less complex scripts to > > figure out which bit masks are actually in use. > > Out of curiousity, why do we care about that list? Originally, I used to track down IO perf issues when porting drivers to ia64. But knowing the dma masks in use on specific platforms might allow folks to disable DMA_ZONE (like ia64 since it's always guarateed either a SWIOTLB or real IOMMU). Any other uses? thanks, grant > > - R. > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- 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/