mtd: nand: relax ecc.read_page() return value for uncorrectable ECC (07604686) · Commits · 戴 / test

The comment for ecc.read_page() requires that it should return "0 if bitflips uncorrectable". Actually, drivers could return positive values when uncorrectable bitflips occur. For example, nand_read_page_swecc() is the case. If ecc.correct() returns -EBADMSG for the first ECC sector, and a positive value for the second one, nand_read_page_swecc() returns a positive max_bitflips and increments ecc_stats.failed for the same page. The requirement can be relaxed by tweaking nand_do_read_ops(). Move the max_bitflips calculation below the retry. Signed-off-by:

Masahiro Yamada <yamada.masahiro@socionext.com> Suggested-by:

Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by:

Boris Brezillon <boris.brezillon@free-electrons.com>

drivers/mtd/nand/nand_base.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -1993,8 +1993,6 @@ read_retry:
		break;
		}

		max_bitflips = max_t(unsigned int, max_bitflips, ret);

		/* Transfer not aligned data */
		if (use_bufpoi) {
		if (!NAND_HAS_SUBPAGE_READ(chip) && !oob &&
		@@ -2045,6 +2043,7 @@ read_retry:
		}

		buf += bytes;
		max_bitflips = max_t(unsigned int, max_bitflips, ret);
		} else {
		memcpy(buf, chip->buffers->databuf + col, bytes);
		buf += bytes;

include/linux/mtd/nand.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -516,7 +516,7 @@ static inline void nand_hw_control_init(struct nand_hw_control *nfc)
		* out-of-band data).
		* @read_page: function to read a page according to the ECC generator
		* requirements; returns maximum number of bitflips corrected in
		* any single ECC step, 0 if bitflips uncorrectable, -EIO hw error
		* any single ECC step, -EIO hw error
		* @read_subpage: function to read parts of the page covered by ECC;
		* returns same as read_page()
		* @write_subpage: function to write parts of the page covered by ECC.

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