[PATCH 2/3] mtd: rawnand: Check the CHANGE_READ_COLUMN from nand_read_subpage() is supported

[Miquel Raynal]

There are constraint controllers which do not support
CHANGE_READ_COLUMNs at any offset. In particular, the offset alignment
might be an issue. Ensure that the operation is supported before trying
it.

Signed-off-by: Miquel Raynal <miquel.raynal at bootlin.com>
---
 drivers/mtd/nand/raw/nand_base.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
index 7f29f27bb6fd..8175635b9802 100644
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -3065,10 +3065,19 @@ static int nand_read_subpage(struct nand_chip *chip, uint32_t data_offs,
 		    (busw - 1))
 			aligned_len++;
 
-		ret = nand_change_read_column_op(chip,
-						 mtd->writesize + aligned_pos,
-						 &chip->oob_poi[aligned_pos],
-						 aligned_len, false);
+		ret = nand_check_change_read_column_op(chip,
+						       mtd->writesize + aligned_pos,
+						       &chip->oob_poi[aligned_pos],
+						       aligned_len, false, true);
+		if (!ret)
+			ret = nand_change_read_column_op(chip,
+							 mtd->writesize + aligned_pos,
+							 &chip->oob_poi[aligned_pos],
+							 aligned_len, false);
+		else
+			ret = nand_change_read_column_op(chip, mtd->writesize,
+							 chip->oob_poi,
+							 mtd->oobsize, false);
 		if (ret)
 			return ret;
 	}
-- 
2.27.0