Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit f29ab49b authored by Geert Uytterhoeven's avatar Geert Uytterhoeven Committed by Christoph Hellwig
Browse files

dma-mapping: Convert NO_DMA get_dma_ops() into a real dummy 



If NO_DMA=y, get_dma_ops() returns a reference to the
non-existing symbol bad_dma_ops, thus causing a link failure if it is
ever used.

Make get_dma_ops() return NULL instead, to avoid the link failure.
This allows to improve compile-testing, and limits the need to keep on
sprinkling dependencies on HAS_DMA all over the place.

Signed-off-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: default avatarMark Brown <broonie@kernel.org>
Acked-by: default avatarRobin Murphy <robin.murphy@arm.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
parent 0c8efd61

include/linux/dma-mapping.h

+5 −5
Original line number Diff line number Diff line
@@ -212,14 +212,14 @@ static inline void set_dma_ops(struct device *dev, 
}

#else

/*

 * Define the dma api to allow compilation but not linking of

 * dma dependent code.  Code that depends on the dma-mapping

 * API needs to set 'depends on HAS_DMA' in its Kconfig

 * Define the dma api to allow compilation of dma dependent code.

 * Code that depends on the dma-mapping API needs to set 'depends on HAS_DMA'

 * in its Kconfig, unless it already depends on <something> || COMPILE_TEST,

 * where <something> guarantuees the availability of the dma-mapping API.

 */

extern const struct dma_map_ops bad_dma_ops;

static inline const struct dma_map_ops *get_dma_ops(struct device *dev)

{

	return &bad_dma_ops;

	return NULL;

}

#endif