Re: [PATCH 2/2] e1000: Fix DMA mapping error handling on RX

[Jeff Kirsher <jeffrey.t.kirsher@intel.com>]

On Thu, Jan 21, 2010 at 03:44, Anton Blanchard <anton@samba.org> wrote:
>
> Check for error return from pci_map_single/pci_map_page and clean up.
>
> With this and the previous patch the driver was able to handle a significant
> percentage of errors (I set the fault injection rate to 10% and could still
> download large files at a reasonable speed).
>
> Signed-off-by: Anton Blanchard <anton@samba.org>
> ---
>
> I wasn't able to stress the jumbo frame path, so that part could do with some
> more eyes.
>
> Index: linux.trees.git/drivers/net/e1000/e1000_main.c
> ===================================================================
> --- linux.trees.git.orig/drivers/net/e1000/e1000_main.c 2010-01-21 11:13:10.000000000 +1100
> +++ linux.trees.git/drivers/net/e1000/e1000_main.c      2010-01-21 11:15:54.000000000 +1100
> @@ -4014,11 +4014,21 @@ check_page:
>                        }
>                }
>
> -               if (!buffer_info->dma)
> +               if (!buffer_info->dma) {
>                        buffer_info->dma = pci_map_page(pdev,
>                                                        buffer_info->page, 0,
>                                                        buffer_info->length,
>                                                        PCI_DMA_FROMDEVICE);
> +                       if (pci_dma_mapping_error(pdev, buffer_info->dma)) {
> +                               put_page(buffer_info->page);
> +                               dev_kfree_skb(skb);
> +                               buffer_info->page = NULL;
> +                               buffer_info->skb = NULL;
> +                               buffer_info->dma = 0;
> +                               adapter->alloc_rx_buff_failed++;
> +                               break; /* while !buffer_info->skb */
> +                       }
> +               }
>
>                rx_desc = E1000_RX_DESC(*rx_ring, i);
>                rx_desc->buffer_addr = cpu_to_le64(buffer_info->dma);
> @@ -4109,6 +4119,13 @@ map_skb:
>                                                  skb->data,
>                                                  buffer_info->length,
>                                                  PCI_DMA_FROMDEVICE);
> +               if (pci_dma_mapping_error(pdev, buffer_info->dma)) {
> +                       dev_kfree_skb(skb);
> +                       buffer_info->skb = NULL;
> +                       buffer_info->dma = 0;
> +                       adapter->alloc_rx_buff_failed++;
> +                       break; /* while !buffer_info->skb */
> +               }
>
>                /*
>                 * XXX if it was allocated cleanly it will never map to a

I have added this patch to my queue of patches for review and testing.  Thanks.

-- 
Cheers,
Jeff