Messages in this thread | | | Date | Fri, 27 Aug 2010 09:26:17 +0900 | Subject | Re: ARM: 2.6.3[45] PCI regression (IXP4xx and PXA?) | From | FUJITA Tomonori <> |
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On Thu, 26 Aug 2010 18:02:46 +0200 Krzysztof Halasa <khc@pm.waw.pl> wrote:
> FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> writes: > > > Lots of drivers call dma_set_coherent_mask with 64bit mask and then > > call it with 32bit mask if 64bit mask fails. > > Which seems strange to me. If the driver asks for 64-bit mask and the > system can only give it 32-bits, why return an error? Every 32-bit > address is also 64-bit, with the most significant bits simply cleared.
As I wrote, the DMA API simply wasn't designed in that way (let architectures to clip the mask), I guess.
If it was, dma_set_coherent_mask might return the actual mask.
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