Add support for ECC maximization when software BCH with
nand_ooblayout_lp_ops layout is used.
Other cases should be handled by the NAND controller driver.
Signed-off-by: Boris Brezillon <boris.brezil...@free-electrons.com>
---
drivers/mtd/nand/nand_base.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index d374129..ca4f53d 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -4224,6 +4224,7 @@ static int nand_set_ecc_soft_ops(struct mtd_info *mtd)
ecc->write_page_raw = nand_write_page_raw;
ecc->read_oob = nand_read_oob_std;
ecc->write_oob = nand_write_oob_std;
+
/*
* Board driver should supply ecc.size and ecc.strength
* values to select how many bits are correctable.
@@ -4246,6 +4247,25 @@ static int nand_set_ecc_soft_ops(struct mtd_info *mtd)
}
mtd_set_ooblayout(mtd, &nand_ooblayout_lp_ops);
+
+ }
+
+ /*
+ * We can only maximize ECC config when the default layout is
+ * used, otherwise we don't know how many bytes can really be
+ * used.
+ */
+ if (mtd->ooblayout == &nand_ooblayout_lp_ops &&
+ ecc->options & NAND_ECC_MAXIMIZE) {
+ int steps, bytes;
+
+ /* Always prefer 1k blocks over 512bytes ones */
+ ecc->size = 1024;
+ steps = mtd->writesize / ecc->size;
+
+ /* Reserve 2 bytes for the BBM */
+ bytes = (mtd->oobsize - 2) / steps;
+ ecc->strength = bytes * 8 / fls(8 * ecc->size);
}
/* See nand_bch_init() for details. */
--
2.7.4
