lkml.org 
[lkml]   [2010]   [Jan]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Hang: 2.6.32.4 sky2/DMAR (was [PATCH] sky2: Fix WARNING: at lib/dma-debug.c:902 check_sync)
On Wed, Jan 27, 2010 at 01:45:27PM -0500, Michael Breuer wrote:
> On 1/27/2010 1:08 PM, Michael Breuer wrote:
> >On 01/27/2010 12:56 PM, Stephen Hemminger wrote:
> >>--- a/drivers/net/sky2.c 2010-01-27 09:46:10.940005248 -0800
> >>+++ b/drivers/net/sky2.c 2010-01-27 09:53:47.141267850 -0800
> >>@@ -2257,13 +2257,16 @@ static struct sk_buff *receive_copy(stru
> >>
> >> skb = netdev_alloc_skb_ip_align(sky2->netdev, length);
> >> if (likely(skb)) {
> >>+ unsigned dma_align = dma_get_cache_alignment();
> >>+ unsigned dma_size = ALIGN(length+1, dma_align);
> >>+
> >> pci_dma_sync_single_for_cpu(sky2->hw->pdev, re->data_addr,
> >>- length, PCI_DMA_FROMDEVICE);
> >>+ dma_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);
> >>+ dma_size, PCI_DMA_FROMDEVICE);
> >> re->skb->ip_summed = CHECKSUM_NONE;
> >> skb_put(skb, length);
> >> }
> >This doesn't apply - I'm missing some intermediate patch.
> >
> >I've got (both in 2.6.32.4 and 2.6.33-rc5: pci_unmap_len(re,
> >data_size) vs., "length." I assume that I can just replace the
> >pci_unmap_len with dma_size... but perhaps the intermediate change
> >may have affected this as well?
> >
> Never mind - that was from one of the earlier patches I had been
> trying out. will try the above patch after reestablishing that the
> system still crashes without copybreak=1.
>

Stephen, I'm not sure this patch can show much after the patch with
"legal" dma_size == re->data_addr didn't help. It looks like David
was right: dma_sync can't affect dmar, because it doesn't use it at
all.

Then I'd rather suggest to test if using copybreak more often, e.g.
with copybreak=1000 or even more can trigger these errors faster.

Jarek P.


\
 
 \ /
  Last update: 2010-01-27 20:25    [from the cache]
©2003-2011 Jasper Spaans