Tejun Heo wrote:
Hello, Robert.

Robert Hancock wrote:
This fixes some problems with ATAPI devices on nForce4 controllers in ADMA
mode on systems with memory located above 4GB. We need to delay setting the
64-bit DMA mask until the PRD table and padding buffer are allocated so that
they don't get allocated above 4GB and break legacy mode (which is needed for
ATAPI devices). Also, explicitly set a 32-bit DMA mask before allocating the
legacy buffers since setting the DMA mask affects both ports and we need to
ensure the second port's buffers are allocated properly (fixes a problem
with the previous version of this patch).

Signed-off-by: Robert Hancock <[EMAIL PROTECTED]>

+       /* Ensure DMA mask is set to 32-bit before allocating legacy PRD and
+          pad buffers */
+       pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
+       pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32));
[--snip--]
+       pci_set_dma_mask(pdev, DMA_BIT_MASK(64));
+       pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64));

I'm probably being paranoid here but please add error checks.  Just
checking return value and returning error suffices.

In the 32-bit case, I'm pretty sure those are guaranteed not to fail because 32-bit is the default. For the 64-bit ones, we don't care if they fail, because then we'll just use whatever mask ends up being set (we store the actual set DMA mask in adma_dma_mask for use when we need to reconfigure the bounce limit). We definitely don't want to fail initialization if the 64-bit set doesn't succeed..
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