one liner DMA mapping fix for 4.20

one liner DMA mapping fix for 4.20

[Christoph Hellwig]

Hi Linus,

I'm sending this directly to you given how late we are.  This is a trivial
one liner fixing a regression I introduces in this merge merge, and which
has only been noticed by code inspection, but which is pretty obvious when
looking at the original commit.  It would be great if it could make 4.20.

[PATCH] dma-mapping: fix flags in dma_alloc_wc

[Christoph Hellwig]

We really need the writecombine flag in dma_alloc_wc, fix a stupid
oversight.

Fixes: 7ed1d91a9e ("dma-mapping: translate __GFP_NOFAIL to DMA_ATTR_NO_WARN")
Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.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 15bd41447025..d327bdd53716 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -796,7 +796,7 @@ static inline void dmam_release_declared_memory(struct device *dev)
 static inline void *dma_alloc_wc(struct device *dev, size_t size,
 				 dma_addr_t *dma_addr, gfp_t gfp)
 {
-	unsigned long attrs = DMA_ATTR_NO_WARN;
+	unsigned long attrs = DMA_ATTR_WRITE_COMBINE;
 
 	if (gfp & __GFP_NOWARN)
 		attrs |= DMA_ATTR_NO_WARN;
-- 
2.19.2