[PATCH] MTD: fix s3c2410 error correction

Matt Reimer
2007-10-19T01:03:42Z

From: Matt Reimer <mreimer@vpop.net>

The single-bit error correction was, well, incorrect. For determing which
bit to correct it was using P1' P2' P4' P8' instead of P1 P2 P4 P8, and
it was using P16' P32' P64' P128' P256' P512' P1024' P2048' instead of
P16 P32 P64 P128 P256 P512 P1024 P2048.

Signed-off-by: Matt Reimer <mreimer@vpop.net>
---
drivers/mtd/nand/s3c2410.c | 26 ++++++++++++--------------
1 files changed, 12 insertions(+), 14 deletions(-)

diff --git a/drivers/mtd/nand/s3c2410.c b/drivers/mtd/nand/s3c2410.c
index 903db18..077fdcc 100644
--- a/drivers/mtd/nand/s3c2410.c
+++ b/drivers/mtd/nand/s3c2410.c
@@ -364,23 +364,21 @@ static int s3c2410_nand_correct_data(struct mtd_info *mtd, u_char *dat,
((diff2 ^ (diff2 >> 1)) & 0x55) == 0x55) {
/* calculate the bit position of the error */

- bit = (diff2 >> 2) & 1;
- bit |= (diff2 >> 3) & 2;
- bit |= (diff2 >> 4) & 4;
+ bit = ((diff2 >> 3) & 1) |
+ ((diff2 >> 4) & 2) |
+ ((diff2 >> 5) & 4);

/* calculate the byte position of the error */

- byte = (diff1 << 1) & 0x80;
- byte |= (diff1 << 2) & 0x40;
- byte |= (diff1 << 3) & 0x20;
- byte |= (diff1 << 4) & 0x10;
-
- byte |= (diff0 >> 3) & 0x08;
- byte |= (diff0 >> 2) & 0x04;
- byte |= (diff0 >> 1) & 0x02;
- byte |= (diff0 >> 0) & 0x01;
-
- byte |= (diff2 << 8) & 0x100;
+ byte = ((diff2 << 7) & 0x100) |
+ ((diff1 << 0) & 0x80) |
+ ((diff1 << 1) & 0x40) |
+ ((diff1 << 2) & 0x20) |
+ ((diff1 << 3) & 0x10) |
+ ((diff0 >> 4) & 0x08) |
+ ((diff0 >> 3) & 0x04) |
+ ((diff0 >> 2) & 0x02) |
+ ((diff0 >> 1) & 0x01);

dev_dbg(info->device, "correcting error bit %d, byte %d\n",
bit, byte);
--
1.5.3.2