From owner-svn-src-head@FreeBSD.ORG Mon Feb 9 00:09:59 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 6EEA5106566C; Mon, 9 Feb 2009 00:09:59 +0000 (UTC) (envelope-from xcllnt@mac.com) Received: from asmtpout022.mac.com (asmtpout022.mac.com [17.148.16.97]) by mx1.freebsd.org (Postfix) with ESMTP id 574D58FC0C; Mon, 9 Feb 2009 00:09:59 +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 asmtp022.mac.com (Sun Java(tm) System Messaging Server 6.3-7.03 (built Aug 7 2008; 32bit)) with ESMTPSA id <0KER00BHAV3ZPZ10@asmtp022.mac.com>; Sun, 08 Feb 2009 16:09:36 -0800 (PST) Message-id: <34EFBA0C-FB99-42DB-BF5C-A889348AD393@mac.com> From: Marcel Moolenaar To: "M. Warner Losh" In-reply-to: <20090208.170515.1031215309.imp@bsdimp.com> Date: Sun, 08 Feb 2009 16:09:35 -0800 References: <200902082254.n18MsxVt037307@svn.freebsd.org> <9E40268E-A2E2-4CAA-AAFE-EB2491175CEE@mac.com> <20090208.170515.1031215309.imp@bsdimp.com> 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: Mon, 09 Feb 2009 00:10:00 -0000 On Feb 8, 2009, at 4:05 PM, M. Warner Losh wrote: > In message: <9E40268E-A2E2-4CAA-AAFE-EB2491175CEE@mac.com> > Marcel Moolenaar writes: > : > : 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? > > I'm not entirely sure either. However, at this stage of the game I'd > rather be a little conservative in what we change and do a more > careful and thorough analysis. Fair enough. -- Marcel Moolenaar xcllnt@mac.com