4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Alexander Couzens <lynxis@xxxxxxx>
commit 6a623e07694437ad09f382a13f76cffc32239a7f upstream.
The old 1-bit hamming layout requires ECC data to be placed at a
fixed offset, and not necessarily at the end of the OOB area.
Add this old layout back in order to fix legacy setups.
Fixes: 41b207a70d3a ("mtd: nand: implement the default mtd_ooblayout_ops")
Signed-off-by: Alexander Couzens <lynxis@xxxxxxx>
Acked-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Brian Norris <computersforpeace@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/mtd/nand/nand_base.c | 70 ++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 69 insertions(+), 1 deletion(-)
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -138,6 +138,74 @@ const struct mtd_ooblayout_ops nand_oobl
};
EXPORT_SYMBOL_GPL(nand_ooblayout_lp_ops);
+/*
+ * Support the old "large page" layout used for 1-bit Hamming ECC where ECC
+ * are placed at a fixed offset.
+ */
+static int nand_ooblayout_ecc_lp_hamming(struct mtd_info *mtd, int section,
+ struct mtd_oob_region *oobregion)
+{
+ struct nand_chip *chip = mtd_to_nand(mtd);
+ struct nand_ecc_ctrl *ecc = &chip->ecc;
+
+ if (section)
+ return -ERANGE;
+
+ switch (mtd->oobsize) {
+ case 64:
+ oobregion->offset = 40;
+ break;
+ case 128:
+ oobregion->offset = 80;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ oobregion->length = ecc->total;
+ if (oobregion->offset + oobregion->length > mtd->oobsize)
+ return -ERANGE;
+
+ return 0;
+}
+
+static int nand_ooblayout_free_lp_hamming(struct mtd_info *mtd, int section,
+ struct mtd_oob_region *oobregion)
+{
+ struct nand_chip *chip = mtd_to_nand(mtd);
+ struct nand_ecc_ctrl *ecc = &chip->ecc;
+ int ecc_offset = 0;
+
+ if (section < 0 || section > 1)
+ return -ERANGE;
+
+ switch (mtd->oobsize) {
+ case 64:
+ ecc_offset = 40;
+ break;
+ case 128:
+ ecc_offset = 80;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (section == 0) {
+ oobregion->offset = 2;
+ oobregion->length = ecc_offset - 2;
+ } else {
+ oobregion->offset = ecc_offset + ecc->total;
+ oobregion->length = mtd->oobsize - oobregion->offset;
+ }
+
+ return 0;
+}
+
+const struct mtd_ooblayout_ops nand_ooblayout_lp_hamming_ops = {
+ .ecc = nand_ooblayout_ecc_lp_hamming,
+ .free = nand_ooblayout_free_lp_hamming,
+};
+
static int check_offs_len(struct mtd_info *mtd,
loff_t ofs, uint64_t len)
{
@@ -4565,7 +4633,7 @@ int nand_scan_tail(struct mtd_info *mtd)
break;
case 64:
case 128:
- mtd_set_ooblayout(mtd, &nand_ooblayout_lp_ops);
+ mtd_set_ooblayout(mtd, &nand_ooblayout_lp_hamming_ops);
break;
default:
WARN(1, "No oob scheme defined for oobsize %d\n",