From owner-svn-src-head@FreeBSD.ORG Sun Feb 8 23:01:29 2009 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 58AF01065673; Sun, 8 Feb 2009 23:01:29 +0000 (UTC) (envelope-from xcllnt@mac.com) Received: from asmtpout017.mac.com (asmtpout017.mac.com [17.148.16.92]) by mx1.freebsd.org (Postfix) with ESMTP id 411008FC0C; Sun, 8 Feb 2009 23:01:29 +0000 (UTC) (envelope-from xcllnt@mac.com) MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Received: from [192.168.4.253] (xcllnt.net [75.101.29.67]) by asmtp017.mac.com (Sun Java(tm) System Messaging Server 6.3-7.03 (built Aug 7 2008; 32bit)) with ESMTPSA id <0KER001UURY9NQ00@asmtp017.mac.com>; Sun, 08 Feb 2009 15:01:22 -0800 (PST) Message-id: <9E40268E-A2E2-4CAA-AAFE-EB2491175CEE@mac.com> From: Marcel Moolenaar To: Warner Losh In-reply-to: <200902082254.n18MsxVt037307@svn.freebsd.org> Date: Sun, 08 Feb 2009 15:01:21 -0800 References: <200902082254.n18MsxVt037307@svn.freebsd.org> X-Mailer: Apple Mail (2.930.3) Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r188350 - in head/sys: amd64/amd64 arm/arm dev/usb2/core i386/i386 ia64/ia64 sys X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 08 Feb 2009 23:01:29 -0000 On Feb 8, 2009, at 2:54 PM, Warner Losh wrote: > Author: imp > Date: Sun Feb 8 22:54:58 2009 > New Revision: 188350 > URL: http://svn.freebsd.org/changeset/base/188350 > > Log: > When bouncing pages, allow a new option to preserve the intra-page > offset. This is needed for the ehci hardware buffer rings that > assume > this behavior. I thought we ended up with always doing that? Bounce buffers may or may not be used, so if the page offset must be zero for bounce buffers, they must be zero for the original DMA request. I see no value in re-aligning the DMA request to a page boundary when bounce buffers are used, but it is required in some cases to not realign. Hence, why not always (and unconditionally) preserve the alignment? -- Marcel Moolenaar xcllnt@mac.com