[PATCH 2/6] mtd: rawnand: sunxi: fix sunxi_nfc_hw_ecc_read_extra_oob

From: Richard Genoud

Date: Fri Feb 20 2026 - 11:11:47 EST


When dumping the OOB, the bytes at the end where actually copied from
the beginning of the OOB instead of current_offset.

That leads to something like:
OOB: ff ff ff ff ff ff ff ff ea 19 00 3a 83 db aa 8d
OOB: 99 09 c8 9a 90 36 35 7d aa 15 13 07 3d 97 b2 a4
OOB: a8 bb 19 b3 07 e9 f6 25 52 d7 1a 23 e2 7e 0a e4
OOB: 52 8a 09 d2 1a 86 3d cf b4 99 43 13 d3 90 33 0b
OOB: ff ff ff ff ff ff ff ff ea 19 00 3a 83 db aa 8d
OOB: 99 09 c8 9a 90 36 35 7d aa 15 13 07 3d 97 b2 a4
OOB: a8 bb 19 b3 07 e9 f6 25 52 d7 1a 23 e2 7e 0a e4
OOB: 52 8a 09 d2 1a 86 3d cf b4 99 43 13 d3 90 33 0b
instead of:
OOB: ff ff ff ff ff ff ff ff ea 19 00 3a 83 db aa 8d
OOB: 99 09 c8 9a 90 36 35 7d aa 15 13 07 3d 97 b2 a4
OOB: a8 bb 19 b3 07 e9 f6 25 52 d7 1a 23 e2 7e 0a e4
OOB: 52 8a 09 d2 1a 86 3d cf b4 99 43 13 d3 90 33 0b
OOB: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
OOB: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
OOB: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
OOB: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
(example with BCH16, user data [8,0], no scrambling)

*cur_off (offset from the beginning of the page) was compared to offset
(offset from the beginning of the OOB), and then, the
nand_change_read_column_op() sets the current position to the beginning
of the OOB instead of OOB+offset

Fixes: 15d6f118285f ("mtd: rawnand: sunxi: Stop supporting ECC_HW_SYNDROME mode")
Signed-off-by: Richard Genoud <richard.genoud@xxxxxxxxxxx>
---
drivers/mtd/nand/raw/sunxi_nand.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/nand/raw/sunxi_nand.c b/drivers/mtd/nand/raw/sunxi_nand.c
index c420909b944b..9c6e0625e34f 100644
--- a/drivers/mtd/nand/raw/sunxi_nand.c
+++ b/drivers/mtd/nand/raw/sunxi_nand.c
@@ -1054,9 +1054,9 @@ static void sunxi_nfc_hw_ecc_read_extra_oob(struct nand_chip *nand,
if (len <= 0)
return;

- if (!cur_off || *cur_off != offset)
- nand_change_read_column_op(nand, mtd->writesize, NULL, 0,
- false);
+ if (!cur_off || *cur_off != (offset + mtd->writesize))
+ nand_change_read_column_op(nand, mtd->writesize + offset,
+ NULL, 0, false);

if (!randomize)
sunxi_nfc_read_buf(nand, oob + offset, len);