Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753925Ab0ATSFP (ORCPT ); Wed, 20 Jan 2010 13:05:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753859Ab0ATSFO (ORCPT ); Wed, 20 Jan 2010 13:05:14 -0500 Received: from smtp1.linux-foundation.org ([140.211.169.13]:35140 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753766Ab0ATSFL (ORCPT ); Wed, 20 Jan 2010 13:05:11 -0500 Date: Wed, 20 Jan 2010 10:03:16 -0800 From: Stephen Hemminger To: Jarek Poplawski Cc: David Miller , Michael Breuer , akpm@linux-foundation.org, flyboy@gmail.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Michael Chan , Don Fry , Francois Romieu , Matt Carlson Subject: Re: [PATCH] sky2: Fix WARNING: at lib/dma-debug.c:902 check_sync Message-ID: <20100120100316.2b5b1b05@nehalam> In-Reply-To: <20100120094103.GA6225@ff.dom.local> References: <20100120094103.GA6225@ff.dom.local> Organization: Linux Foundation X-Mailer: Claws Mail 3.7.2 (GTK+ 2.18.3; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2605 Lines: 68 On Wed, 20 Jan 2010 09:41:03 +0000 Jarek Poplawski wrote: > [ previously: Re: [PATCH] af_packet: Don't use skb after dev_queue_xmit() ] > On Tue, Jan 19, 2010 at 05:10:13PM -0800, Stephen Hemminger wrote: > > On Tue, 19 Jan 2010 20:01:10 -0500 > > Michael Breuer wrote: > > > > > On 1/19/2010 5:45 PM, Jarek Poplawski wrote: > > > > On Tue, Jan 19, 2010 at 03:06:01PM -0500, Michael Breuer wrote: > > > > > > > >> On 1/19/2010 2:59 PM, Jarek Poplawski wrote: > > > >> > > > >>> On Tue, Jan 19, 2010 at 10:47:27AM -0500, Michael Breuer wrote: > > > >>> ... > > > >>> > > > >>>> Still get the warning... but now 60 bytes. > > > >>>> Jan 19 10:43:50 mail kernel: ------------[ cut here ]------------ > > > >>>> Jan 19 10:43:50 mail kernel: WARNING: at lib/dma-debug.c:902 > ... > > > That not only compiled, but it cleared the error as well. Additionally, > > > I used to see a bit of a delay receiving the login prompt when first > > > connecting to the box by ssh. That delay is gone with this patch. I'd > > > guess that the warning wasn't quite as innocuous as I thought. > > > Note: tested on 2.6.32.4. I'll leave this up for a bit before > > > attempting to move back to head. > > > > Seems like an underlying bug in the DMA api. Maybe it just can't > > handle operations on partial mapping. > > > > Other drivers with same problem: > > bnx2, cassini, pcnet32, r8169, rrunner, skge, sungem, tg3, > > It seems using the same length (even without pci_unmap_len()) is > crucial here, but I hope maintainers (added to CC) will take care. > > Btw, it's not tested yet, but it might affect CONFIG_DMAR problems. The list of places to inspect is: $ git grep -l sync_single_for_cpu $(git grep -l skb_copy_from_linear_data) drivers/infiniband/ulp/ipoib/ipoib_cm.c drivers/message/fusion/mptlan.c drivers/net/b44.c drivers/net/bnx2.c drivers/net/cassini.c drivers/net/chelsio/sge.c drivers/net/cxgb3/sge.c drivers/net/irda/vlsi_ir.c drivers/net/myri_sbus.c drivers/net/r8169.c drivers/net/rrunner.c drivers/net/skge.c drivers/net/sky2.c drivers/net/sungem.c drivers/net/sunhme.c drivers/net/tg3.c drivers/net/tokenring/3c359.c drivers/net/tokenring/olympic.c drivers/net/tulip/de2104x.c drivers/net/via-velocity.c drivers/net/wireless/ipw2x00/ipw2100.c drivers/net/wireless/ipw2x00/ipw2200.c -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/