dma-mapping: return an error code from dma_mapping_error

Currently dma_mapping_error returns a boolean as int, with 1 meaning
error.  This is rather unusual and many callers have to convert it to
errno value.  The callers are highly inconsistent with error codes
ranging from -ENOMEM over -EIO, -EINVAL and -EFAULT ranging to -EAGAIN.
Return -ENOMEM which seems to be what the largest number of callers
convert it to, and which also matches the typical error case where
we are out of resources.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index f4ac26d..7799c2b 100644 (file)
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -582,7 +582,7 @@ static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
        debug_dma_mapping_error(dev, dma_addr);
 
        if (dma_addr == DMA_MAPPING_ERROR)
-               return 1;
+               return -ENOMEM;
        return 0;
 }