From b14b9d25a3c707c85e7e31e15766a71365b52ab7 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Fri, 30 Nov 2018 10:59:37 +0100
Subject: [PATCH] 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>
---
 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 f4ac26d5294a0..7799c2b278499 100644
--- 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;
 }
 
-- 
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