On Thu, 2013-09-19 at 17:13 +0100, Ben Hutchings wrote:
> [Re-sending with cc to the current stable address. I still had the old
> address in contacts, though I've definitely sent to the current address
> previously...]
>
> This bug fix is only for stable branches older than 3.10. The bug was
> fixed upstream by commit 2768935a4660 ('sfc: reuse pages to avoid DMA
> mapping/unmapping costs'), but that change is totally unsuitable for
> stable.
>
> Commit b590ace09d51 ('sfc: Fix efx_rx_buf_offset() in the presence of
> swiotlb') added an explicit page_offset member to struct
> efx_rx_buffer, which must be set consistently with the u.page and
> dma_addr fields. However, it failed to add the necessary assignment
> in efx_resurrect_rx_buffer(). It also did not correct the calculation
> of efx_rx_buffer::dma_addr in efx_resurrect_rx_buffer(), which assumes
> that DMA-mapping a page will result in a page-aligned DMA address
> (exactly what swiotlb violates).
>
> Add the assignment of efx_rx_buffer::page_offset and change the
> calculation of dma_addr to make use of it.
>
> I'm attaching the patches for 3.0.y, 3.2.y and 3.4.y (the last of which
> should also be applicable to the later unofficial stable branches).
Queued up for 3.2.
Ben.
--
Ben Hutchings
Tomorrow will be cancelled due to lack of interest.
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