| Message ID | 20100119224508.GA3473@del.dom.local |
|---|---|
| State | RFC, archived |
| Delegated to: | David Miller |
| Headers | show |
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 >>>> >>> Thanks for trying this. >>> Jarek P. >>> >> NP. Let me know what else I can do to help with this one. Note that >> it seems innocuous. I'll continue with the older set and no dmar for >> now and see if I get another crash. >> > Maybe one more idea to try (not compiled). > > Jarek P. > --- > > 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); > } > 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. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, 19 Jan 2010 20:01:10 -0500 Michael Breuer <mbreuer@majjas.com> 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 > >>>> > >>> Thanks for trying this. > >>> Jarek P. > >>> > >> NP. Let me know what else I can do to help with this one. Note that > >> it seems innocuous. I'll continue with the older set and no dmar for > >> now and see if I get another crash. > >> > > Maybe one more idea to try (not compiled). > > > > Jarek P. > > --- > > > > 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); > > } > > > 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,
Stephen Hemminger wrote: > On Tue, 19 Jan 2010 20:01:10 -0500 > Michael Breuer <mbreuer@majjas.com> wrote: >> On 1/19/2010 5:45 PM, Jarek Poplawski wrote: [...] >> > --- 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); >> > } >> > >> 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, I didn't read the start of this thread and may misunderstand the issue, but I comment anyway...: Documentation/DMA-API.txt says the following about (pci_)dma_sync_single and friends: "All the parameters must be the same as those passed into the single mapping API." http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob;f=Documentation/DMA-API.txt;h=5aceb88b3f8b622c8c23ed288f37f42de705c904;hb=HEAD#l367 So, it might be considered an API bug --- but it is a documented one. :-)
Stefan Richter wrote: > I didn't read the start of this thread and may misunderstand the issue, > but I comment anyway...: > > Documentation/DMA-API.txt says the following about (pci_)dma_sync_single > and friends: "All the parameters must be the same as those passed into > the single mapping API." > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob;f=Documentation/DMA-API.txt;h=5aceb88b3f8b622c8c23ed288f37f42de705c904;hb=HEAD#l367 > > So, it might be considered an API bug --- but it is a documented one. :-) Disregard my comment. I just noticed that there is more qualified discussion of this in the thread "[PATCH] sky2: Fix WARNING: at lib/dma-debug.c:902 check_sync".
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); }