lkml.org 
[lkml]   [2016]   [Apr]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] mtd: nand: s3c2410: fix bug in s3c2410_nand_correct_data()
Date
From: Zeng Zhaoxiu <zhaoxiu.zeng@gmail.com>

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.

Here, we can use the simple expression "(diff0 & (diff0 - 1)) == 0" to determine
whether the diff0 has only one 1-bit.
---
drivers/mtd/nand/s3c2410.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/s3c2410.c b/drivers/mtd/nand/s3c2410.c
index 9c9397b..c9698cf 100644
--- a/drivers/mtd/nand/s3c2410.c
+++ b/drivers/mtd/nand/s3c2410.c
@@ -542,7 +542,7 @@ 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)
+ if ((diff0 & (diff0 - 1)) == 0)
return 1;

return -1;
--
2.5.5

\
 
 \ /
  Last update: 2016-04-07 19:01    [W:0.083 / U:0.356 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site