mtd: nand: s3c2410: fix bug in s3c2410_nand_correct_data()

If there is only one bit difference in the ECC, the function should
return 1.
The result of "diff0 & ~(1<<fls(diff0))" is equal to diff0, so the
function actually returns -1.

Signed-off-by: Zhaoxiu Zeng <zhaoxiu.zeng@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

diff --git a/drivers/mtd/nand/s3c2410.c b/drivers/mtd/nand/s3c2410.c
index 9c9397b54b2ca9a826e27fc7625108100ae2fb87..86ffb73e10853b9ac22dfce93bb5a85984b2cfdf 100644 (file)
--- a/drivers/mtd/nand/s3c2410.c
+++ b/drivers/mtd/nand/s3c2410.c
@@ -542,7 +542,8 @@ static int s3c2410_nand_correct_data(struct mtd_info *mtd, u_char *dat,
        diff0 |= (diff1 << 8);
        diff0 |= (diff2 << 16);
 
-       if ((diff0 & ~(1<<fls(diff0))) == 0)
+       /* equal to "(diff0 & ~(1 << __ffs(diff0)))" */
+       if ((diff0 & (diff0 - 1)) == 0)
                return 1;
 
        return -1;