mtd: nand: initialize bitflip_threshold prior to BBT scanning
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 <c00cbc2b736c26791a3822db86f8796fe9efff67@pengutronix.de>
Tested-by: Sascha Hauer <c00cbc2b736c26791a3822db86f8796fe9efff67@pengutronix.de>
Signed-off-by: Shmulik Ladkani <17d95d1f97e0668e532c695f667f3a3b359c14b2@gmail.com>
Signed-off-by: Artem Bityutskiy <2f96f8cd3e2780a209d0ab27d1b44624d0019d3f@linux.intel.com>
Signed-off-by: David Woodhouse <b460d66aaf00c296a3db1c1d9eeafc081d5f7d70@intel.com>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas