From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752628AbYDXOSo (ORCPT ); Thu, 24 Apr 2008 10:18:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751797AbYDXOSg (ORCPT ); Thu, 24 Apr 2008 10:18:36 -0400 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:37940 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751623AbYDXOSf (ORCPT ); Thu, 24 Apr 2008 10:18:35 -0400 Date: Thu, 24 Apr 2008 07:18:35 -0700 (PDT) Message-Id: <20080424.071835.06112189.davem@davemloft.net> To: mb@bu3sch.de Cc: andi@firstfloor.org, linux-kernel@vger.kernel.org, vojtech@suse.cz, muli@il.ibm.com, jdmason@kudzu.us, tglx@linutronix.de, mingo@redhat.com Subject: Re: [PATCH RFC] x86: Fix 64-bit DMA masks on VIA From: David Miller In-Reply-To: <200804241606.00883.mb@bu3sch.de> References: <200804232055.13102.mb@bu3sch.de> <87mynjgyg9.fsf@basil.nowhere.org> <200804241606.00883.mb@bu3sch.de> X-Mailer: Mew version 5.2 on Emacs 22.1 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Michael Buesch Date: Thu, 24 Apr 2008 16:06:00 +0200 > Why do we need to workaround this in _every_ driver? (Note that _every_ > driver supporting a 64bit mask is affected). Why not fix it in the DMA layer? Because the driver has to make a conscious choice of what DMA mask it wants to use. Datastructures can change based upon whether 32-bit or 64-bit DMA is available, etc.