> Isochronous reception in dualbuffer is reportedly broken with
> TI TSB43AB22A on x86-64. Descriptor addresses above 2G have been
> determined as the trigger:
>
https://bugzilla.redhat.com/show_bug.cgi?id=435550
>
> Two fixes are possible:
> - pci_set_consistent_dma_mask(pdev, DMA_31BIT_MASK);
> at least when IR descriptors are allocated, or
> - simply don't use dualbuffer.
> This fix implements the latter workaround.
>
> But we keep using dualbuffer on x86-32 which won't give us highmen (and
> thus physical addresses outside the 31bit range) in coherent DMA memory
> allocations. Right now we could for example also whitelist PPC32, but
> DMA mapping implementation details are expected to change there.
>
> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
