On 5/6/2015 5:08 AM, Robin Murphy wrote:

[...]

quoted

+static void __dummy_sync_single_for_cpu(struct device *dev,
+                    dma_addr_t dev_addr, size_t size,
+                    enum dma_data_direction dir)
+{
+}
+
+static void __dummy_sync_single_for_device(struct device *dev,
+                       dma_addr_t dev_addr, size_t size,
+                       enum dma_data_direction dir)
+{
+}

Minor point, but I don't see the need to have multiple dummy functions
with identical signatures - just have a generic dummy_sync_single and
assign it to both ops.

quoted

+static void __dummy_sync_sg_for_cpu(struct device *dev,
+                    struct scatterlist *sgl, int nelems,
+                    enum dma_data_direction dir)
+{
+}
+
+static void __dummy_sync_sg_for_device(struct device *dev,
+                       struct scatterlist *sgl, int nelems,
+                       enum dma_data_direction dir)
+{
+}

Ditto here with dummy_sync_sg.

Hi Robin,

Good point. I'll take care of that in V3.

I wonder if there's any argument for putting the dummy DMA ops somewhere
common, like drivers/base/dma-mapping.c?

Robin.

Hm.. If this approach will be adopted by other architectures, then it 
would make sense. Currently, this is only used by arm64. So, I think it 
is okay to leave this here for now.

Thanks,
Suravee