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: Ricardo Ribalda Delgado <[email protected]> --- include/linux/dma-mapping.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index c3007cb..ac07ff0 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -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); -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
