From owner-svn-src-all@FreeBSD.ORG Mon Feb 9 14:39:37 2009 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 9BED2106572A; Mon, 9 Feb 2009 14:39:37 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from cyrus.watson.org (cyrus.watson.org [65.122.17.42]) by mx1.freebsd.org (Postfix) with ESMTP id 666B68FC37; Mon, 9 Feb 2009 14:39:37 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from server.baldwin.cx (pool-98-109-39-197.nwrknj.fios.verizon.net [98.109.39.197]) by cyrus.watson.org (Postfix) with ESMTPSA id DBC4E46B03; Mon, 9 Feb 2009 09:39:36 -0500 (EST) Received: from localhost (john@localhost [127.0.0.1]) (authenticated bits=0) by server.baldwin.cx (8.14.3/8.14.3) with ESMTP id n19EdPWG004084; Mon, 9 Feb 2009 09:39:30 -0500 (EST) (envelope-from jhb@freebsd.org) From: John Baldwin To: Marcel Moolenaar Date: Mon, 9 Feb 2009 09:23:45 -0500 User-Agent: KMail/1.9.7 References: <200902082254.n18MsxVt037307@svn.freebsd.org> <498F8015.8000704@samsco.org> <94616FBD-4638-4C51-990C-06A943B1BA2A@mac.com> In-Reply-To: <94616FBD-4638-4C51-990C-06A943B1BA2A@mac.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200902090923.45887.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH authentication, not delayed by milter-greylist-2.0.2 (server.baldwin.cx [127.0.0.1]); Mon, 09 Feb 2009 09:39:30 -0500 (EST) X-Virus-Scanned: ClamAV 0.94.2/8967/Mon Feb 9 03:38:55 2009 on server.baldwin.cx X-Virus-Status: Clean X-Spam-Status: No, score=-4.4 required=4.2 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.1.3 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on server.baldwin.cx Cc: svn-src-head@freebsd.org, Scott Long , src-committers@freebsd.org, svn-src-all@freebsd.org, "M. Warner Losh" Subject: Re: svn commit: r188350 - in head/sys: amd64/amd64 arm/arm dev/usb2/core i386/i386 ia64/ia64 sys X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 09 Feb 2009 14:39:40 -0000 On Monday 09 February 2009 12:37:53 am Marcel Moolenaar wrote: > > On Feb 8, 2009, at 5:00 PM, Scott Long wrote: > > > Busdma allows you to request bouncing for realignment. > > How exactly? The 'align' parameter to bus_dma_tag_create(). If your hardware needs buffers to be aligned on a 4-byte boundary and you bus_dmamap_load() a buffer where 'addr % 4 != 0', then the buffer is bounced. Since by default the new buffer starts on a page boundary, it satifies the 'addr % 4'. -- John Baldwin