[PATCH] drm/cma: Use dma_mmap_writecombine() to mmap buffer

[Philipp Zabel]

On Sun, Mar 2, 2014 at 8:09 PM, Laurent Pinchart
<laurent.pinchart+renesas at ideasonboard.com> wrote:
> The GEM CMA helpers uses a custom mmap implementation based on
> remap_pfn_range(). While this works when the buffer DMA and physical
> addresses are identical, it fails to take IOMMU into account and tries
> to mmap the buffer to userspace using the DMA virtual address instead of
> the physical address. This results in mapping random physical pages when
> the device is behind an IOMMU.
>
> Use the DMA mapping dma_mmap_writecombine() function instead.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas at ideasonboard.com>

Tested-by: Philipp Zabel <philipp.zabel at gmail.com>

regards
Philipp