Commit f306e8c3 authored Mar 20, 2014 by pekon gupta Committed by Brian Norris May 20, 2014

mtd: nand: omap: fix BCHx ecc.correct to return detected bit-flips in erased-page



fixes: commit 62116e51
       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>

parent 9ab86995

drivers/mtd/nand/omap2.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1382,7 +1382,7 @@ static int omap_elm_correct_data(struct mtd_info mtd, u_char data,

		/* Check if any error reported */
		if (!is_error_reported)
		return 0;
		return stat;

		/* Decode BCH error using ELM module */
		elm_decode_bch_error_page(info->elm_dev, ecc_vec, err_vec);

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