diff mbox series

[v6,6/6] mtd: rawnand: micron: detect forced on-die ECC

Message ID 20180624224448.21872-7-chris.packham@alliedtelesis.co.nz
State Accepted
Delegated to: Miquel Raynal
Headers show
Series mtd: rawnand: support MT29F1G08ABAFAWP-ITE:F | expand

Commit Message

Chris Packham June 24, 2018, 10:44 p.m. UTC 
Some Micron NAND chips have on-die ECC forceably enabled. Detect these
based on chip ID as there seems to be no other way of distinguishing
these chips from those that have optional support for on-die ECC.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
---
Changes in v4:
- New
Changes in v5:
- fail if on-die ECC is mandatory and the current ecc.mode is not
  NAND_ECC_ON_DIE.
Changes in v6:
- Update commit message, add review from Boris

 drivers/mtd/nand/raw/nand_micron.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/mtd/nand/raw/nand_micron.c b/drivers/mtd/nand/raw/nand_micron.c
index f83053562925..35fa6880a799 100644
--- a/drivers/mtd/nand/raw/nand_micron.c
+++ b/drivers/mtd/nand/raw/nand_micron.c
@@ -255,6 +255,14 @@  enum {
 	MICRON_ON_DIE_MANDATORY,
 };
 
+/*
+ * These parts are known to have on-die ECC forceably enabled
+ */
+static u8 micron_on_die_ecc[] = {
+	0xd1, /* MT29F1G08ABAFA */
+	0xa1, /* MT29F1G08ABBFA */
+};
+
 /*
  * Try to detect if the NAND support on-die ECC. To do this, we enable
  * the feature, and read back if it has been enabled as expected. We
@@ -269,6 +277,11 @@  static int micron_supports_on_die_ecc(struct nand_chip *chip)
 {
 	u8 feature[ONFI_SUBFEATURE_PARAM_LEN] = { 0, };
 	int ret;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(micron_on_die_ecc); i++)
+		if (chip->id.data[1] == micron_on_die_ecc[i])
+			return MICRON_ON_DIE_MANDATORY;
 
 	if (!chip->parameters.onfi.version)
 		return MICRON_ON_DIE_UNSUPPORTED;
@@ -322,7 +335,8 @@  static int micron_nand_init(struct nand_chip *chip)
 
 	ondie = micron_supports_on_die_ecc(chip);
 
-	if (ondie == MICRON_ON_DIE_MANDATORY) {
+	if (ondie == MICRON_ON_DIE_MANDATORY &&
+	    chip->ecc.mode != NAND_ECC_ON_DIE) {
 		pr_err("On-die ECC forcefully enabled, not supported\n");
 		return -EINVAL;
 	}