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| author | Shmulik Ladkani <shmulik@jungo.com> | 2012-06-08 18:29:06 +0300 |
|---|---|---|
| committer | David Woodhouse <David.Woodhouse@intel.com> | 2012-06-09 12:02:04 +0100 |
| commit | ea3b2ea24ef0f2ef9c6795b19cff456195b6728a (patch) | |
| tree | 8a1c645a82a7329631166cf6e3f63857d401da40 | |
| parent | cfaf025112d3856637ff34a767ef785ef5cf2ca9 (diff) | |
| download | op-kernel-dev-ea3b2ea24ef0f2ef9c6795b19cff456195b6728a.zip op-kernel-dev-ea3b2ea24ef0f2ef9c6795b19cff456195b6728a.tar.gz | |
mtd: nand: initialize bitflip_threshold prior to BBT scanning
As of edbc454 [mtd: driver _read() returns max_bitflips; mtd_read()
returns -EUCLEAN], 'mtd->bitflip_threshold' must be set for mtd devices
having ECC, prior any 'mtd_read()' call.
Otherwise, 'mtd_read()' will falsely return -EUCLEAN.
Normally, 'mtd->bitflip_threshold' is initialized when the MTD is added.
However, this is too late for NAND MTDs, as 'scan_bbt()' is invoked
prior the existing initialization of 'mtd->bitflip_threshold'.
This is a problem since 'scan_bbt()' calls 'mtd_read()', in the case
of a flash-based bad block table.
It resulted in a falsely reported bitflips indication during BBT read,
which lead to constant scrubbing of the flash BBT blocks.
Initialize 'mtd->bitflip_threshold' to its default value (if not already
set by the driver), prior to invocation of 'scan_bbt()'.
Reported-by: Sascha Hauer <s.hauer@pengutronix.de>
Tested-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.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/nand_base.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index d47586c..a11253a0 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -3501,6 +3501,13 @@ int nand_scan_tail(struct mtd_info *mtd) /* propagate ecc info to mtd_info */ mtd->ecclayout = chip->ecc.layout; mtd->ecc_strength = chip->ecc.strength; + /* + * Initialize bitflip_threshold to its default prior scan_bbt() call. + * scan_bbt() might invoke mtd_read(), thus bitflip_threshold must be + * properly set. + */ + if (!mtd->bitflip_threshold) + mtd->bitflip_threshold = mtd->ecc_strength; /* Check, if we should skip the bad block table scan */ if (chip->options & NAND_SKIP_BBTSCAN) |
