From owner-svn-src-head@FreeBSD.ORG Fri Jun 11 17:53:19 2010 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 27C51106566B; Fri, 11 Jun 2010 17:53:19 +0000 (UTC) (envelope-from xcllnt@mac.com) Received: from asmtpout029.mac.com (asmtpout029.mac.com [17.148.16.104]) by mx1.freebsd.org (Postfix) with ESMTP id 060228FC0A; Fri, 11 Jun 2010 17:53:19 +0000 (UTC) MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: text/plain; charset=us-ascii Received: from macbook-pro.lan.xcllnt.net (mail.xcllnt.net [75.101.29.67]) by asmtp029.mac.com (Sun Java(tm) System Messaging Server 6.3-8.01 (built Dec 16 2008; 32bit)) with ESMTPSA id <0L3V00J2W30MIK60@asmtp029.mac.com>; Fri, 11 Jun 2010 10:53:12 -0700 (PDT) X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 ipscore=0 phishscore=0 bulkscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx engine=6.0.2-1004200000 definitions=main-1006110114 X-Proofpoint-Virus-Version: vendor=fsecure engine=1.12.8161:2.4.5,1.2.40,4.0.166 definitions=2010-06-11_02:2010-02-06, 2010-06-11, 2010-06-11 signatures=0 From: Marcel Moolenaar In-reply-to: <896621F6-4BAF-43D4-9D97-29B4EF34C080@samsco.org> Date: Fri, 11 Jun 2010 10:53:10 -0700 Message-id: References: <201006110300.o5B30X9q045387@svn.freebsd.org> <201006110751.40735.jhb@freebsd.org> <853068F6-D736-4DA3-859F-D946D096843D@samsco.org> <19B0DF11-5998-40F5-8095-8D2521B1C597@mac.com> <291D17F7-F387-4A13-8ED9-2898A9F7E018@mac.com> <028BA7D4-90C8-4D2D-B9A5-C1C3CF9B6D7D@samsco.org> <53158C9B-C9E1-4C47-B361-83C76181721A@mac.com> <896621F6-4BAF-43D4-9D97-29B4EF34C080@samsco.org> To: Scott Long X-Mailer: Apple Mail (2.1078) Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org, John Baldwin Subject: Re: svn commit: r209026 - in head/sys/ia64: ia64 include 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: Fri, 11 Jun 2010 17:53:19 -0000 On Jun 11, 2010, at 10:47 AM, Scott Long wrote: > On Jun 11, 2010, at 11:44 AM, Marcel Moolenaar wrote: >> >> On Jun 11, 2010, at 10:37 AM, Scott Long wrote: >>> >>> I'm not clear why you even need bounce buffers for RX. The chip supports 64bit addresses with no boundary or alignment restrictions. >> >> As per: >> /* >> * All controllers that are not 5755 or higher have 4GB >> * boundary DMA bug. >> * Whenever an address crosses a multiple of the 4GB boundary >> * (including 4GB, 8Gb, 12Gb, etc.) and makes the transition >> * from 0xX_FFFF_FFFF to 0x(X+1)_0000_0000 an internal DMA >> * state machine will lockup and cause the device to hang. >> */ >> if (BGE_IS_5755_PLUS(sc) == 0) >> sc->bge_flags |= BGE_FLAG_4G_BNDRY_BUG; >> >> and: >> lowaddr = BUS_SPACE_MAXADDR; >> if ((sc->bge_flags & BGE_FLAG_40BIT_BUG) != 0) >> lowaddr = BGE_DMA_MAXADDR; >> if ((sc->bge_flags & BGE_FLAG_4G_BNDRY_BUG) != 0) >> lowaddr = BUS_SPACE_MAXADDR_32BIT; >> /* >> * Allocate the parent bus DMA tag appropriate for PCI. >> */ >> error = bus_dma_tag_create(bus_get_dma_tag(sc->bge_dev), >> 1, 0, lowaddr, BUS_SPACE_MAXADDR, NULL, >> NULL, BUS_SPACE_MAXSIZE_32BIT, 0, BUS_SPACE_MAXSIZE_32BIT, >> 0, NULL, NULL, &sc->bge_cdata.bge_parent_tag); >> >> > > Noted in previous email. If this restriction is put in the boundary attribute, then you'll only bounce the very rare case of an mbuf straddling a 4G boundary. I agree with you, but I was just giving the facts. I don't even know if we attempted to use the boundary argument before but problems forced us to resort to this. -- Marcel Moolenaar xcllnt@mac.com