[PATCH 23/23] dma-mapping: return an error code from dma_mapping_error

[Christoph Hellwig <hch@xxxxxx>]

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@xxxxxx>
---
 include/linux/dma-mapping.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 2adef56c6069..b5bd25fc1f81 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -576,7 +576,7 @@ 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;
 }
 
-- 
2.19.1