From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752492Ab0ATJlS (ORCPT ); Wed, 20 Jan 2010 04:41:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752245Ab0ATJlQ (ORCPT ); Wed, 20 Jan 2010 04:41:16 -0500 Received: from fg-out-1718.google.com ([72.14.220.153]:62637 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752010Ab0ATJlL (ORCPT ); Wed, 20 Jan 2010 04:41:11 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:mime-version:content-type :content-disposition:user-agent; b=CqjC+4MAbqPFa+xSETBT/rM3mt8kVj/gmql23q2SxN++zACRh4GfGXbyoUcdzg1dMk WrLqzlCxpqsjrvVRaGuaue0QIm2siSjaPWKsL6C67Ur/JF+IVRe959grDwP3n9MewHf+ vP/3j5L4s13ppviLeHwBdvahb8Rw39BQQLMQs= Date: Wed, 20 Jan 2010 09:41:03 +0000 From: Jarek Poplawski To: David Miller Cc: Stephen Hemminger , 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: [PATCH] sky2: Fix WARNING: at lib/dma-debug.c:902 check_sync Message-ID: <20100120094103.GA6225@ff.dom.local> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ 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. Thanks, Jarek P. -----------------------> Using pci_unmap_len(), with the same length as pci_map_single(), with pci_dma_sync_single_for_cpu()/_device() fixes this warning (2.6.32.4): > Jan 19 10:43:50 mail kernel: WARNING: at lib/dma-debug.c:902 > check_sync+0xc1/0x43f() > Jan 19 10:43:50 mail kernel: Hardware name: System Product Name > Jan 19 10:43:50 mail kernel: sky2 0000:04:00.0: DMA-API: device driver > tries to sync DMA memory it has not allocated [device > address=0x0000000320a0b022] [size=60 bytes] Reported-by: Michael Breuer Tested-by: Michael Breuer Signed-off-by: Jarek Poplawski --- drivers/net/sky2.c | 6 ++++-- 1 files changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c index 7650f73..cdebdd3 100644 --- a/drivers/net/sky2.c +++ b/drivers/net/sky2.c @@ -2252,12 +2252,14 @@ static struct sk_buff *receive_copy(struct sky2_port *sky2, skb = netdev_alloc_skb_ip_align(sky2->netdev, length); if (likely(skb)) { pci_dma_sync_single_for_cpu(sky2->hw->pdev, re->data_addr, - length, PCI_DMA_FROMDEVICE); + pci_unmap_len(re, data_size), + PCI_DMA_FROMDEVICE); skb_copy_from_linear_data(re->skb, skb->data, length); skb->ip_summed = re->skb->ip_summed; skb->csum = re->skb->csum; pci_dma_sync_single_for_device(sky2->hw->pdev, re->data_addr, - length, PCI_DMA_FROMDEVICE); + pci_unmap_len(re, data_size), + PCI_DMA_FROMDEVICE); re->skb->ip_summed = CHECKSUM_NONE; skb_put(skb, length); }