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authorMarco Felsch2019-07-30 15:44:07 +0200
committerGreg Kroah-Hartman2019-08-06 19:06:54 +0200
commite7bb4c81b3c791c7eab7fbfc2a312c7442aad5a6 (patch)
tree4b9b1d9095c8b416bdc02a4a6d3f7a64fd43d04a
parentIB/hfi1: Fix Spectre v1 vulnerability (diff)
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mtd: rawnand: micron: handle on-die "ECC-off" devices correctly
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>
-rw-r--r--drivers/mtd/nand/raw/nand_micron.c14
1 files changed, 11 insertions, 3 deletions
diff --git a/drivers/mtd/nand/raw/nand_micron.c b/drivers/mtd/nand/raw/nand_micron.c
index f5dc0a7a2456..fb401c25732c 100644
--- 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(struct nand_chip *chip)
(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(struct nand_chip *chip)
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;