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authorJosh Wu <josh.wu@atmel.com>2013-08-19 12:05:44 +0200
committerDavid Woodhouse <David.Woodhouse@intel.com>2013-08-30 22:41:39 +0200
commit2fa831f9db1f1a13960f4ea0fd0454402717b453 (patch)
tree97c4bbba2a72689cf85ff627f62c1f6b87640e4f
parentmtd: m25p80: Micron SPI uses Macronix-style 4-byte addressing (diff)
downloadlinux-2fa831f9db1f1a13960f4ea0fd0454402717b453.tar.xz
linux-2fa831f9db1f1a13960f4ea0fd0454402717b453.zip
mtd: atmel_nand: pmecc: fix failure to correct bit error in 1024-bytes sector
The PMECC use BCH algorithm to correct error. In BCH algorithm, the primitive polynomial value is GF(2^13) for 512-bytes sector size. And it is GF(2^14) for 1024-bytes sector size. This patch will choose correct degree of the remainders (13 or 14) for different sector size. Tested in AT91SAM9X5-EK with MLC nand flash. More detail can be found in ยง5.4.1 of: AT91SAM ARM-based Embedded MPU Application Note <http://www.atmel.com/Images/doc11127.pdf> Signed-off-by: Josh Wu <josh.wu@atmel.com> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
-rw-r--r--drivers/mtd/nand/atmel_nand.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
index 0e365daad9cc..8b2eb3e5896b 100644
--- a/drivers/mtd/nand/atmel_nand.c
+++ b/drivers/mtd/nand/atmel_nand.c
@@ -1204,7 +1204,8 @@ static int __init atmel_pmecc_nand_init_params(struct platform_device *pdev,
/* set ECC page size and oob layout */
switch (mtd->writesize) {
case 2048:
- host->pmecc_degree = PMECC_GF_DIMENSION_13;
+ host->pmecc_degree = (sector_size == 512) ?
+ PMECC_GF_DIMENSION_13 : PMECC_GF_DIMENSION_14;
host->pmecc_cw_len = (1 << host->pmecc_degree) - 1;
host->pmecc_sector_number = mtd->writesize / sector_size;
host->pmecc_bytes_per_sector = pmecc_get_ecc_bytes(