mtd: nand: relax ecc.read_page() return value for uncorrectable ECC
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>
diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 4065793..9e0c93c 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -516,7 +516,7 @@
* 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.