Re: [E1000-devel] [PATCH 07/51] DMA-API: net: intel/ixgbe: fix 32-bit DMA mask handling

[Jeff K. <jef...@in...>]

On Thu, 2013-09-19 at 22:31 +0100, Russell King wrote:
> The fallback to 32-bit DMA mask is rather odd:
>         if (!dma_set_mask(&pdev->dev, DMA_BIT_MASK(64)) &&
>             !dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(64))) {
>                 pci_using_dac = 1;
>         } else {
>                 err = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
>                 if (err) {
>                         err = dma_set_coherent_mask(&pdev->dev,
>                                                     DMA_BIT_MASK(32));
>                         if (err) {
>                                 dev_err(&pdev->dev,
>                                         "No usable DMA configuration,
> aborting\n");
>                                 goto err_dma;
>                         }
>                 }
>                 pci_using_dac = 0;
>         }
> This means we only set the coherent DMA mask in the fallback path if
> the DMA mask set failed, which is silly.  This fixes it to set the
> coherent DMA mask only if dma_set_mask() succeeded, and to error out
> if either fails.
> 
> Signed-off-by: Russell King <rmk...@ar...>
> ---
>  drivers/net/ethernet/intel/ixgbe/ixgbe_main.c |   15 +++++----------
>  1 files changed, 5 insertions(+), 10 deletions(-)

Acked-by: Jeff Kirsher <jef...@in...>