[RESEND PATCH v2 0/2] mtd: core: NAND erase preparation

[RESEND PATCH v2 0/2] mtd: core: NAND erase preparation

[Bean Huo (beanhuo)]

On some legacy planar 2D Micron NAND devices when a
block erase command is issued, occasionally even
though a block erase operation successfully completes
and returns a pass status, the flash block may not be
completely erased. Subsequent operations to this block
on very rare cases can result in subtle failures or
corruption. These extremely rare cases should nevertheless
be considered.

These rare occurrences have been observed on partially 
written blocks. Partially written blocks are not uncommon
with UBI/UBIFS.

To avoid this rare occurrence, we make sure that at least
15 pages have been programmed to a block before it is erased.
In case we find that less than 15 pages have been programmed,
additional pages are programmed in the block. The observation
is that additional pages rarely need to be written and most of
the time UBI/UBIFS erases blocks that contain more programmed
pages.

Change log:

v1-v2:
  Rebased V1 to latest Linux kernel.
  Add erase preparation function pointer in nand_manufacturer_ops.
	 
 
Signed-off-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: ZOLTAN SZUBBOCSEV <zszubbocsev@micron.com>

Bean Huo (2):
  mtd: core: add erase preparation hook function pointer
  mtd: core: NAND filling block

 drivers/mtd/nand/raw/internals.h   |   2 +
 drivers/mtd/nand/raw/nand_base.c   |   5 ++
 drivers/mtd/nand/raw/nand_micron.c | 119 +++++++++++++++++++++++++++++++++++++
 3 files changed, 126 insertions(+)

-- 
2.7.4

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