mtd: rawnand: sunxi: fix sunxi_nfc_hw_ecc_read_extra_oob

[ Upstream commit 848c139 ]

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: 15d6f11 ("mtd: rawnand: sunxi: Stop supporting ECC_HW_SYNDROME mode")
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Richard Genoud <richard.genoud@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: richard-bootlin

drivers/mtd/nand/raw/sunxi_nand.c

@@ -886,9 +886,9 @@ 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);