mtd: nand: fix incorrect ecc strength values

This fixes a couple of ecc strength values for which I earlier made conservative
guesses, but whose correct values were later determined¹ (thanks Ivan).  Also
sets strength for fsl_ifc_nand, which was merged to mainline after the original
patch that set the strength for all drivers.

¹ http://lists.infradead.org/pipermail/linux-mtd/2012-March/040325.html

Signed-off-by: Mike Dunn <mikedunn@newsguy.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

diff --git a/drivers/mtd/nand/bcm_umi_nand.c b/drivers/mtd/nand/bcm_umi_nand.c
index 6908cdd..7134adf 100644 (file)
--- a/drivers/mtd/nand/bcm_umi_nand.c
+++ b/drivers/mtd/nand/bcm_umi_nand.c
@@ -476,12 +476,7 @@ static int __devinit bcm_umi_nand_probe(struct platform_device *pdev)
                this->badblock_pattern = &largepage_bbt;
        }
 
-       /*
-        * FIXME: ecc strength value of 6 bits per 512 bytes of data is a
-        * conservative guess, given 13 ecc bytes and using bch alg.
-        * (Assume Galois field order m=15 to allow a margin of error.)
-        */
-       this->ecc.strength = 6;
+       this->ecc.strength = 8;
 
 #endif
 

diff --git a/drivers/mtd/nand/fsl_ifc_nand.c b/drivers/mtd/nand/fsl_ifc_nand.c
index 5387cec..872cc96 100644 (file)
--- a/drivers/mtd/nand/fsl_ifc_nand.c
+++ b/drivers/mtd/nand/fsl_ifc_nand.c
@@ -821,6 +821,7 @@ static int fsl_ifc_chip_init(struct fsl_ifc_mtd *priv)
        /* Hardware generates ECC per 512 Bytes */
        chip->ecc.size = 512;
        chip->ecc.bytes = 8;
+       chip->ecc.strength = 4;
 
        switch (csor & CSOR_NAND_PGS_MASK) {
        case CSOR_NAND_PGS_512:

diff --git a/drivers/mtd/nand/jz4740_nand.c b/drivers/mtd/nand/jz4740_nand.c
index e4147e8..a6fa884 100644 (file)
--- a/drivers/mtd/nand/jz4740_nand.c
+++ b/drivers/mtd/nand/jz4740_nand.c
@@ -332,11 +332,7 @@ static int __devinit jz_nand_probe(struct platform_device *pdev)
        chip->ecc.mode          = NAND_ECC_HW_OOB_FIRST;
        chip->ecc.size          = 512;
        chip->ecc.bytes         = 9;
-       chip->ecc.strength      = 2;
-       /*
-        * FIXME: ecc_strength value of 2 bits per 512 bytes of data is a
-        * conservative guess, given 9 ecc bytes and reed-solomon alg.
-        */
+       chip->ecc.strength      = 4;
 
        if (pdata)
                chip->ecc.layout = pdata->ecc_layout;