On Sun, 27 Aug 2017, Christoph Hellwig wrote:
> x86 does not implement DMA_ATTR_NON_CONSISTENT allocations, so it doesn't
> make any sense to do any work in dma_cache_sync given that it must be a
> no-op when dma_alloc_attrs returns coherent memory.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx
Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> ---
> arch/x86/include/asm/dma-mapping.h | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
> index 398c79889f5c..04877267ad18 100644
> --- a/arch/x86/include/asm/dma-mapping.h
> +++ b/arch/x86/include/asm/dma-mapping.h
> @@ -70,7 +70,6 @@ static inline void
> dma_cache_sync(struct device *dev, void *vaddr, size_t size,
> enum dma_data_direction dir)
> {
> - flush_write_buffers();
> }
>
> static inline unsigned long dma_alloc_coherent_mask(struct device *dev,
> --
> 2.11.0
>
>
