ppc4xx: Fix ECC Correction bug with SMC ordering for NDFC driver

Fix ECC Correction bug where the byte offset location were double
flipped causing correction routine to toggle the wrong byte location
in the ECC segment. The ndfc_calculate_ecc routine change the order
of getting the ECC code.
        /* The NDFC uses Smart Media (SMC) bytes order */
        ecc_code[0] = p[2];
        ecc_code[1] = p[1];
        ecc_code[2] = p[3];
But in the Correction algorithm when calculating the byte offset
location, the s1 is used as the upper part of the address. Which
again reverse the order making the final byte offset address
location incorrect.
	byteoffs = (s1 << 0) & 0x80;
	.
	.
	byteoffs |= (s0 >> 4) & 0x08;
The order is change to read it in straight and let the correction
function to revert it to SMC order.

Signed-off-by: Feng Kan <[email protected]>
Acked-by: Victor Gallardo <[email protected]>
Acked-by: Prodyut Hazarika <[email protected]>
Signed-off-by: Stefan Roese <[email protected]>

diff --git a/drivers/mtd/nand/ndfc.c b/drivers/mtd/nand/ndfc.c
index 528b22b49aeb32ec2a57720d385a080c12bd9a8d..0891936f00d4c2776b296750cd1e57a8861caa0e 100644 (file)
--- a/drivers/mtd/nand/ndfc.c
+++ b/drivers/mtd/nand/ndfc.c
@@ -89,8 +89,8 @@ static int ndfc_calculate_ecc(struct mtd_info *mtdinfo,
 
        /* The NDFC uses Smart Media (SMC) bytes order
         */
-       ecc_code[0] = p[2];
-       ecc_code[1] = p[1];
+       ecc_code[0] = p[1];
+       ecc_code[1] = p[2];
        ecc_code[2] = p[3];
 
        return 0;