From owner-svn-src-all@FreeBSD.ORG Fri Jun 11 18:36:20 2010 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 2E0EC106566B; Fri, 11 Jun 2010 18:36:20 +0000 (UTC) (envelope-from scottl@samsco.org) Received: from pooker.samsco.org (pooker.samsco.org [168.103.85.57]) by mx1.freebsd.org (Postfix) with ESMTP id C03038FC24; Fri, 11 Jun 2010 18:36:19 +0000 (UTC) Received: from [127.0.0.1] (pooker.samsco.org [168.103.85.57]) (authenticated bits=0) by pooker.samsco.org (8.14.4/8.14.4) with ESMTP id o5BIaGHB040216; Fri, 11 Jun 2010 12:36:16 -0600 (MDT) (envelope-from scottl@samsco.org) Mime-Version: 1.0 (Apple Message framework v1078) Content-Type: text/plain; charset=us-ascii From: Scott Long In-Reply-To: <20100611183049.GH13776@michelle.cdnetworks.com> Date: Fri, 11 Jun 2010 12:36:16 -0600 Content-Transfer-Encoding: quoted-printable Message-Id: <9CACE2BA-ACA1-44B5-A325-20F5A12BE187@samsco.org> References: <201006110300.o5B30X9q045387@svn.freebsd.org> <9F065122-7D91-42E9-A251-5AF4AAF0B4E5@samsco.org> <20100611175016.GD13776@michelle.cdnetworks.com> <201006111420.46919.jhb@freebsd.org> <20100611183049.GH13776@michelle.cdnetworks.com> To: pyunyh@gmail.com X-Mailer: Apple Mail (2.1078) X-Spam-Status: No, score=-50.0 required=3.8 tests=ALL_TRUSTED, T_RP_MATCHES_RCVD autolearn=unavailable version=3.3.0 X-Spam-Checker-Version: SpamAssassin 3.3.0 (2010-01-18) on pooker.samsco.org Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, Marcel Moolenaar , src-committers@freebsd.org, John Baldwin Subject: Re: svn commit: r209026 - in head/sys/ia64: ia64 include 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: Fri, 11 Jun 2010 18:36:20 -0000 On Jun 11, 2010, at 12:30 PM, Pyun YongHyeon wrote: > On Fri, Jun 11, 2010 at 02:20:46PM -0400, John Baldwin wrote: >>>>>>=20 >>>>>> I'm not clear why you even need bounce buffers for RX. The chip=20= >> supports 64bit addresses with no boundary or alignment restrictions. >>>>>>=20 >>>>>=20 >>>>> Some controllers have 4G boundary bug so bge(4) restricts dma >>>>> address space. >>>>=20 >>>> That limitation should be reflected in the boundary attribute of = the tag,=20 >> not the lowaddr/highaddr attributes. >>>>=20 >>>=20 >>> Yes, but that needed more code. And I don't have these buggy >>> controllers so I chose more simple way that would work even though >>> it may be inefficient. >>=20 >> You can just use a 2GB boundary as a workaround. Look at what the = twa(4)=20 >> driver does to enforce a 4GB boundary for an example. >>=20 >=20 > I vaguely remember the problem was DMA memory allocated with > bus_dmamem_alloc(9) does not honor boundary argument so bge(4) had > to ensure the allocated memory is within 4GB. That might be true, in which case you should set the restriction on the = child tags that need it, not the parent tag. Scott