Patchwork [v2,06/13] nand/fsmc: Initialize the badblockbits to 7

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Submitter Vipin Kumar
Date March 14, 2012, 6:17 a.m.
Message ID <>
Download mbox | patch
Permalink /patch/146548/
State New, archived
Headers show


Vipin Kumar - March 14, 2012, 6:17 a.m.
Ideally, the block should have 0xff written on the bad block position. Any value
other than 0xff implies a bad block. In practical situations, there can be
bit flips in the oob area as well which means that a block with 0x7f being read
at bad block position may imply a bad block but it is infact only a bit flip in
the bad block byte.

To resolve this problem, the block is marked as good if number of high bits is
greater than or equal to badblockbits (initialized to 7)

Signed-off-by: Vipin Kumar <>
 drivers/mtd/nand/fsmc_nand.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)


diff --git a/drivers/mtd/nand/fsmc_nand.c b/drivers/mtd/nand/fsmc_nand.c
index 745db62..bfc924f 100644
--- a/drivers/mtd/nand/fsmc_nand.c
+++ b/drivers/mtd/nand/fsmc_nand.c
@@ -802,6 +802,7 @@  static int __init fsmc_nand_probe(struct platform_device *pdev)
 	nand->ecc.size = 512;
 	nand->options = pdata->options;
 	nand->select_chip = fsmc_select_chip;
+	nand->badblockbits = 7;
 	if (pdata->width == FSMC_NAND_BW16)
 		nand->options |= NAND_BUSWIDTH_16;