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From:   Alexander Egorenkov <egorenar-dev@posteo.net>
To:     linux-kernel@vger.kernel.org
Cc:     Alexander Egorenkov <egorenar-dev@posteo.net>
Subject: [PATCH 1/1] lib: scatterlist: Fix SGL length in sg_split() if !CONFIG_NEED_SG_DMA_LENGTH
Date:   Sun, 18 Apr 2021 08:14:41 +0000
Message-Id: <20210418081441.5040-1-egorenar-dev@posteo.net>
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If CONFIG_NEED_SG_DMA_LENGTH is NOT enabled then sg_dma_len() is an alias
for the length field in a SGL. In that case sg_split() wrongly resets
the length of split SGLs to zero after it was set correctly before.

Signed-off-by: Alexander Egorenkov <egorenar-dev@posteo.net>
---
 lib/sg_split.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/sg_split.c b/lib/sg_split.c
index 60a0babebf2e..3d9b32084d78 100644
--- a/lib/sg_split.c
+++ b/lib/sg_split.c
@@ -92,7 +92,8 @@ static void sg_split_phys(struct sg_splitter *splitters, const int nb_splits)
 				out_sg->offset = 0;
 			}
 			sg_dma_address(out_sg) = 0;
-			sg_dma_len(out_sg) = 0;
+			if (IS_ENABLED(CONFIG_NEED_SG_DMA_LENGTH))
+				sg_dma_len(out_sg) = 0;
 			in_sg = sg_next(in_sg);
 		}
 		out_sg[-1].length = split->length_last_sg;
-- 
2.31.1