[PATCH v2 3/5] ARM: dma-mapping: Implement arch_iommu_detach_device()

[Christoph Hellwig]

> +void arch_iommu_detach_device(struct device *dev)
> +{
> +#ifdef CONFIG_ARM_DMA_USE_IOMMU
> +	struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
> +	const struct dma_map_ops *dma_ops;
> +
> +	if (!mapping)
> +		return;
> +
> +	arm_iommu_release_mapping(mapping);
> +	arm_iommu_detach_device(dev);
> +
> +	dma_ops = arm_get_dma_map_ops(dev->archdata.dma_coherent);
> +	set_dma_ops(dev, dma_ops);

Why not simply:

	set_dma_ops(dev, arm_get_dma_map_ops(dev->archdata.dma_coherent));