Re: problem with blk_queue_bounce_limit()

[David S. Miller]

Ok, ide-lib.c can call blk_queue_bounce_limit with only
3 different args:

1) BLK_BOUNCE_HIGH (--> blk_max_pfn)
2) BLK_BOUNCE_ANY (--> blk_max_lo_pfn)
3) pci_dev->dma_mask

David, you're not setting PCI_DMA_BUS_IS_PHYS properly.
For IOMMU it should be set to zero.  This tells the block
layer if you're IOMMU or not.

I knew it would be a bug like this.

Anyways, the problem case is #3 above and that will never
happen if you start setting PCI_DMA_BUS_IS_PHYS to zero
as appropriate.