Re: [PATCH] firewire: fw-ohci: TSB43AB22/A dualbuffer workaround

From: Jarod Wilson
Date: Tue Jul 22 2008 - 18:11:40 EST

On Tuesday 22 July 2008 12:41:10 pm Stefan Richter wrote:
> Isochronous reception in dualbuffer is reportedly broken with
> TI TSB43AB22A on x86-64. Descriptor addresses above 2G have been
> determined as the trigger:
> 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@xxxxxxxxxxxxxxxxx>

Still hoping we can get some confirmation of a chipset bug or a fix from TI
for this controller, but in the interim, this seems to be the most reasonable
route to go right now.

Signed-off-by: Jarod Wilson <jwilson@xxxxxxxxxx>

Jarod Wilson
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