[PATCH v1] mtd: rawnand: micron: don't error out if internal ECC is set

From: zdhays
Date: Fri Jan 10 2020 - 11:25:07 EST


From: Zak Hays <zdhays@xxxxxxxxx>

Recent changes to the driver require use of on-die correction if
the internal ECC enable bit is set. On some Micron parts, this bit
is enabled by default and there is no method for disabling it.

This is a false assumption though as that bit being enabled does not
necessarily mean that the on-die ECC *has* to be used. It has been
verified with a Micron FAE that other methods of error correction are
still valid even if this bit is set.

HW ECC offers generally higher performance than on-die so it is
preferred in some situations. This also allows multiple NAND parts to
be supported on the same PCB as some parts may not support on-die
error correction.

With that in mind, only throw a warning that the on-die bit is set
and allow the init to continue.

Signed-off-by: Zak Hays <zdhays@xxxxxxxxx>
---
drivers/mtd/nand/raw/nand_micron.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/mtd/nand/raw/nand_micron.c b/drivers/mtd/nand/raw/nand_micron.c
index 56654030ec7f..ec40c76443be 100644
--- a/drivers/mtd/nand/raw/nand_micron.c
+++ b/drivers/mtd/nand/raw/nand_micron.c
@@ -455,9 +455,7 @@ static int micron_nand_init(struct nand_chip *chip)

if (ondie == MICRON_ON_DIE_MANDATORY &&
chip->ecc.mode != NAND_ECC_ON_DIE) {
- pr_err("On-die ECC forcefully enabled, not supported\n");
- ret = -EINVAL;
- goto err_free_manuf_data;
+ pr_warn("WARNING: On-die ECC forcefully enabled, use caution with other methods\n");
}

if (chip->ecc.mode == NAND_ECC_ON_DIE) {
--
2.17.1