mtd: nand: omap: fix ecclayout->oobfree->offset

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Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=aa6092f9835893290e77c3e24649def49dac1583
Commit:     aa6092f9835893290e77c3e24649def49dac1583
Parent:     eae39cb4934d3daab3ec828c5201c955b2e56af9
Author:     Pekon Gupta <pekon at ti.com>
AuthorDate: Mon Feb 17 13:11:24 2014 +0530
Committer:  Brian Norris <computersforpeace at gmail.com>
CommitDate: Sun Feb 23 14:49:57 2014 -0800

    mtd: nand: omap: fix ecclayout->oobfree->offset
    
    1) In current implementation, ecclayout->oobfree->offset is calculated with
     respect to ecclayout->eccpos[0] which is incorrect because ECC bytes may not
     be stored contiguously in OOB.
     So, this patch calculates ecclayout->oobfree->offset with respect to last
     ECC byte-position 'eccpos[ecclayout->eccbytes-1]'.
    
    2) ECC layout of some ecc-schemes expects reserved-markers at specific eccpos[]
     which should not be over-written by any file-system metadata.
     So this patch aligns oobfree->offset taking into account of such markers.
    
    CC: <stable at vger.kernel.org> # 3.13.x+
    Tested-by: Enric Balletbo i Serra <eballetbo at gmail.com>
    Tested-by: Stefan Roese <sr at denx.de>
    Signed-off-by: Pekon Gupta <pekon at ti.com>
    Signed-off-by: Brian Norris <computersforpeace at gmail.com>
---
 drivers/mtd/nand/omap2.c | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index 34ef941..58685ab 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -1832,8 +1832,9 @@ static int omap_nand_probe(struct platform_device *pdev)
 			oob_index		= 1;
 		for (i = 0; i < ecclayout->eccbytes; i++, oob_index++)
 			ecclayout->eccpos[i]	= oob_index;
-		ecclayout->oobfree->offset	= ecclayout->eccpos[0] +
-							ecclayout->eccbytes;
+		/* no reserved-marker in ecclayout for this ecc-scheme */
+		ecclayout->oobfree->offset	=
+				ecclayout->eccpos[ecclayout->eccbytes - 1] + 1;
 		break;
 
 	case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW:
@@ -1856,8 +1857,9 @@ static int omap_nand_probe(struct platform_device *pdev)
 			if (((i + 1) % nand_chip->ecc.bytes) == 0)
 				oob_index++;
 		}
-		ecclayout->oobfree->offset	= ecclayout->eccpos[0] +
-							ecclayout->eccbytes;
+		/* include reserved-marker in ecclayout->oobfree calculation */
+		ecclayout->oobfree->offset	= 1 +
+				ecclayout->eccpos[ecclayout->eccbytes - 1] + 1;
 		/* software bch library is used for locating errors */
 		nand_chip->ecc.priv		= nand_bch_init(mtd,
 							nand_chip->ecc.size,
@@ -1894,8 +1896,9 @@ static int omap_nand_probe(struct platform_device *pdev)
 		oob_index			= BADBLOCK_MARKER_LENGTH;
 		for (i = 0; i < ecclayout->eccbytes; i++, oob_index++)
 			ecclayout->eccpos[i]	= oob_index;
-		ecclayout->oobfree->offset	= ecclayout->eccpos[0] +
-							ecclayout->eccbytes;
+		/* reserved marker already included in ecclayout->eccbytes */
+		ecclayout->oobfree->offset	=
+				ecclayout->eccpos[ecclayout->eccbytes - 1] + 1;
 		/* This ECC scheme requires ELM H/W block */
 		if (is_elm_present(info, pdata->elm_of_node, BCH4_ECC) < 0) {
 			pr_err("nand: error: could not initialize ELM\n");
@@ -1929,8 +1932,9 @@ static int omap_nand_probe(struct platform_device *pdev)
 			if (((i + 1) % nand_chip->ecc.bytes) == 0)
 				oob_index++;
 		}
-		ecclayout->oobfree->offset	= ecclayout->eccpos[0] +
-							ecclayout->eccbytes;
+		/* include reserved-marker in ecclayout->oobfree calculation */
+		ecclayout->oobfree->offset	= 1 +
+				ecclayout->eccpos[ecclayout->eccbytes - 1] + 1;
 		/* software bch library is used for locating errors */
 		nand_chip->ecc.priv		= nand_bch_init(mtd,
 							nand_chip->ecc.size,
@@ -1974,8 +1978,9 @@ static int omap_nand_probe(struct platform_device *pdev)
 		oob_index			= BADBLOCK_MARKER_LENGTH;
 		for (i = 0; i < ecclayout->eccbytes; i++, oob_index++)
 			ecclayout->eccpos[i]	= oob_index;
-		ecclayout->oobfree->offset	= ecclayout->eccpos[0] +
-							ecclayout->eccbytes;
+		/* reserved marker already included in ecclayout->eccbytes */
+		ecclayout->oobfree->offset	=
+				ecclayout->eccpos[ecclayout->eccbytes - 1] + 1;
 		break;
 #else
 		pr_err("nand: error: CONFIG_MTD_NAND_OMAP_BCH not enabled\n");