Hi Christoph,
On Tue, Apr 14, 2020 at 02:25:05PM +0200, Christoph Hellwig wrote:
> +static inline bool dma_map_direct(struct device *dev,
> + const struct dma_map_ops *ops)
> +{
> + if (likely(!ops))
> + return true;
> + if (!dev->dma_ops_bypass)
> + return false;
> +
> + return min_not_zero(*dev->dma_mask, dev->bus_dma_limit) >=
> + dma_direct_get_required_mask(dev);
Why is the dma-mask check done here? The dma-direct code handles memory
outside of the devices dma-mask with swiotlb, no?
I also don't quite get what the difference between setting the
dma_ops_bypass flag non-zero and setting ops to NULL is.
Joerg
