[PATCH/RFC] dma-mapping: Provide dummy set_dma_ops() for NO_DMA=y

From: Geert Uytterhoeven
Date: Sun Jul 09 2017 - 15:34:05 EST

Adding a dummy for set_dma_ops() allows to compile (sub)drivers that
don't actually use the DMA API, but propagate DMA ops configuration to a
second driver that may or may not use the DMA API. Of course the second
driver does have to depend on HAS_DMA if it uses the DMA API.

An example is commit 5567e989198b5a8d ("fsl/fman: propagate dma_ops").

This allows to revert commit 85688d9adf685572 ("fsl/fman: add dependency
on HAS_DMA").

Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
include/linux/dma-mapping.h | 2 ++
1 file changed, 2 insertions(+)

diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 843ab866e0f487c2..0ab244b954418e2b 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -194,6 +194,8 @@ static inline const struct dma_map_ops *get_dma_ops(struct device *dev)
return &bad_dma_ops;
+static inline void set_dma_ops(struct device *dev,
+ const struct dma_map_ops *dma_ops) {}

static inline dma_addr_t dma_map_single_attrs(struct device *dev, void *ptr,