Re: [PATCH 2/3] dma: Introduce dma_max_mapping_size()

Christoph Hellwig
2019-01-15T13:37:58Z

> +size_t dma_direct_max_mapping_size(struct device *dev)
> +{
> + /*
> + * Return the minimum of the direct DMA limit and the SWIOTLB limit.
> + * Since direct DMA has no limit, it is fine to just return the SWIOTLB
> + * limit.
> + */
> + return swiotlb_max_mapping_size(dev);

Well, if we don't actually use the swiotlb buffers despite it being
compiled in or even allocated we don't need the limit.