[Linaro-mm-sig] [PATCH 3/8] ARM: dma-mapping: use asm-generic/dma-mapping-common.h

[KyongHo Cho]

Hi.

Great job.

On Mon, Jun 20, 2011 at 4:50 PM, Marek Szyprowski
<m.szyprowski at samsung.com> wrote:
> +static inline void set_dma_ops(struct device *dev, struct dma_map_ops *ops)
> +{
> +       dev->archdata.dma_ops = ops;
> +}
> +

Who calls set_dma_ops()?
In the mach. initialization part?
What if a device driver does not want to use arch's dma_map_ops
when machine init procedure set a dma_map_ops?
Even though, may arch defiens their dma_map_ops in archdata of device structure,
I think it is not a good idea that is device structure contains a
pointer to dma_map_ops
that may not be common to all devices in a board.

I also think that it is better to attach and to detach dma_map_ops dynamically.
Moreover, a mapping is not permanent in our Exynos platform
because a System MMU may be turned off while runtime.

DMA API must come with IOMMU API to initialize IOMMU in runtime.

Regards,
Cho KyongHo.