Commit 04abab69 authored by Ricardo Ribalda Delgado's avatar Ricardo Ribalda Delgado Committed by Marek Szyprowski

include/dma-mapping: Clarify output of dma_map_sg

Although dma_map_sg returns 0 on error and it cannot return a
value < 0, the function returns a signed integer.

Most of the time, this function is used with a scatterlist structure.
This structure uses an unsigned integer for the number of memory.

A dma developer that has not read in detail DMA-API.txt, can wrongly
return a value < 0 on error.
Signed-off-by: default avatarRicardo Ribalda Delgado <>
Signed-off-by: default avatarMarek Szyprowski <>
parent 8582e267
......@@ -34,6 +34,10 @@ struct dma_map_ops {
void (*unmap_page)(struct device *dev, dma_addr_t dma_handle,
size_t size, enum dma_data_direction dir,
struct dma_attrs *attrs);
* map_sg returns 0 on error and a value > 0 on success.
* It should never return a value < 0.
int (*map_sg)(struct device *dev, struct scatterlist *sg,
int nents, enum dma_data_direction dir,
struct dma_attrs *attrs);
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