mtd: nand: sunxi: Fix ECC strength choice

When the requested ECC strength does not exactly match the strengths
supported by the ECC engine, the driver is selecting the closest
strength meeting the 'selected_strength > requested_strength'
constraint. Fix the fact that, in this particular case, ecc->strength
value was not updated to match the 'selected_strength'.

For instance, one can encounter this issue when no ECC requirement is
filled in the device tree while the NAND chip minimum requirement is not
a strength/step_size combo natively supported by the ECC engine.

Fixes: 1fef62c1423b ("mtd: nand: add sunxi NAND flash controller support")
Cc: <stable@vger.kernel.org>
Suggested-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Miquel Raynal <miquel.raynal@free-electrons.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

diff --git a/drivers/mtd/nand/sunxi_nand.c b/drivers/mtd/nand/sunxi_nand.c
index 2275fbedfb2ac23d788710b3f1d64e6a289f320d..f5a55c63935cbc80f8fc23c5040025096347f6cf 100644 (file)
--- a/drivers/mtd/nand/sunxi_nand.c
+++ b/drivers/mtd/nand/sunxi_nand.c
@@ -1858,8 +1858,14 @@ static int sunxi_nand_hw_common_ecc_ctrl_init(struct mtd_info *mtd,
 
        /* Add ECC info retrieval from DT */
        for (i = 0; i < ARRAY_SIZE(strengths); i++) {
-               if (ecc->strength <= strengths[i])
+               if (ecc->strength <= strengths[i]) {
+                       /*
+                        * Update ecc->strength value with the actual strength
+                        * that will be used by the ECC engine.
+                        */
+                       ecc->strength = strengths[i];
                        break;
+               }
        }
 
        if (i >= ARRAY_SIZE(strengths)) {