mtd: nand: omap: fix BCHx ecc.correct to return detected bit-flips in erased-page
authorpekon gupta <pekon@ti.com>
Thu, 20 Mar 2014 13:19:58 +0000 (18:49 +0530)
committerBrian Norris <computersforpeace@gmail.com>
Tue, 20 May 2014 23:32:17 +0000 (16:32 -0700)
commitf306e8c3b667632952f1a4a74ffb910bbc06255f
treefcefd08db04a0106077e81d503a02f778dc07857
parent9ab86995ed07f51c45ba1b549aff2bd6e46590e9
mtd: nand: omap: fix BCHx ecc.correct to return detected bit-flips in erased-page

fixes: commit 62116e5171e00f85a8d53f76e45b84423c89ff34
       mtd: nand: omap2: Support for hardware BCH error correction.

In omap_elm_correct_data(), if bitflip_count in an erased-page is within the
correctable limit (< ecc.strength), then it is not indicated back to the caller
ecc->read_page().

This mis-guides upper layers like MTD and UBIFS layer to assume erased-page as
perfectly clean and use it for writing even if actual bitflip_count was
dangerously high (bitflip_count > mtd->bitflip_threshold).

This patch fixes this above issue, by returning 'stats' to caller
ecc->read_page() under all scenarios.

Reported-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Pekon Gupta <pekon@ti.com>
Cc: <stable@vger.kernel.org> # 3.9.x+
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
drivers/mtd/nand/omap2.c