From: Marco Felsch m.felsch@pengutronix.de
commit 8493b2a06fc5b77ef5c579dc32b12761f7b7a84c upstream.
Some devices are not supposed to support on-die ECC but experience shows that internal ECC machinery can actually be enabled through the "SET FEATURE (EFh)" command, even if a read of the "READ ID Parameter Tables" returns that it is not.
Currently, the driver checks the "READ ID Parameter" field directly after having enabled the feature. If the check fails it returns immediately but leaves the ECC on. When using buggy chips like MT29F2G08ABAGA and MT29F2G08ABBGA, all future read/program cycles will go through the on-die ECC, confusing the host controller which is supposed to be the one handling correction.
To address this in a common way we need to turn off the on-die ECC directly after reading the "READ ID Parameter" and before checking the "ECC status".
Cc: stable@vger.kernel.org Fixes: dbc44edbf833 ("mtd: rawnand: micron: Fix on-die ECC detection logic") Signed-off-by: Marco Felsch m.felsch@pengutronix.de Reviewed-by: Boris Brezillon boris.brezillon@collabora.com Signed-off-by: Miquel Raynal miquel.raynal@bootlin.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/mtd/nand/raw/nand_micron.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-)
--- a/drivers/mtd/nand/raw/nand_micron.c +++ b/drivers/mtd/nand/raw/nand_micron.c @@ -400,6 +400,14 @@ static int micron_supports_on_die_ecc(st (chip->id.data[4] & MICRON_ID_INTERNAL_ECC_MASK) != 0x2) return MICRON_ON_DIE_UNSUPPORTED;
+ /* + * It seems that there are devices which do not support ECC officially. + * At least the MT29F2G08ABAGA / MT29F2G08ABBGA devices supports + * enabling the ECC feature but don't reflect that to the READ_ID table. + * So we have to guarantee that we disable the ECC feature directly + * after we did the READ_ID table command. Later we can evaluate the + * ECC_ENABLE support. + */ ret = micron_nand_on_die_ecc_setup(chip, true); if (ret) return MICRON_ON_DIE_UNSUPPORTED; @@ -408,13 +416,13 @@ static int micron_supports_on_die_ecc(st if (ret) return MICRON_ON_DIE_UNSUPPORTED;
- if (!(id[4] & MICRON_ID_ECC_ENABLED)) - return MICRON_ON_DIE_UNSUPPORTED; - ret = micron_nand_on_die_ecc_setup(chip, false); if (ret) return MICRON_ON_DIE_UNSUPPORTED;
+ if (!(id[4] & MICRON_ID_ECC_ENABLED)) + return MICRON_ON_DIE_UNSUPPORTED; + ret = nand_readid_op(chip, 0, id, sizeof(id)); if (ret) return MICRON_ON_DIE_UNSUPPORTED;