Micron MT29F1G08ABAFAWP-ITE:F supports an on-die ECC with 8 bits per 512 bytes. Add support for this combination.
Signed-off-by: Chris Packham <[email protected]> --- Changes in v2: - New Changes in v3: - Handle reporting of corrected errors that don't require a rewrite, expand comment for the ECC status bits. Changes in v4: - Use a switch statement for handling ECC status - Update ecc_stats.corrected drivers/mtd/nand/raw/nand_micron.c | 68 ++++++++++++++++++++---------- 1 file changed, 46 insertions(+), 22 deletions(-) diff --git a/drivers/mtd/nand/raw/nand_micron.c b/drivers/mtd/nand/raw/nand_micron.c index d30bd4df9b12..f1ecd4986b50 100644 --- a/drivers/mtd/nand/raw/nand_micron.c +++ b/drivers/mtd/nand/raw/nand_micron.c @@ -18,10 +18,28 @@ #include <linux/mtd/rawnand.h> /* - * Special Micron status bit that indicates when the block has been - * corrected by on-die ECC and should be rewritten + * Special Micron status bit 3 indicates that the block has been + * corrected by on-die ECC and should be rewritten. + * + * On chips with 8-bit ECC and additional bit can be used to distinguish + * cases where a errors were corrected without needing a rewrite + * + * Bit 4 Bit 3 Bit 0 Description + * ----- ----- ----- ----------- + * 0 0 0 No Errors + * 0 0 1 Multiple uncorrected errors + * 0 1 0 4 - 6 errors corrected, recommend rewrite + * 0 1 1 Reserved + * 1 0 0 1 - 3 errors corrected + * 1 0 1 Reserved + * 1 1 0 7 - 8 errors corrected, recommend rewrite */ -#define NAND_STATUS_WRITE_RECOMMENDED BIT(3) +#define NAND_STATUS_MASK (BIT(4) | BIT(3) | BIT(0)) +#define NAND_STATUS_NO_ERRORS 0 +#define NAND_STATUS_UNCORRECTABLE BIT(0) +#define NAND_STATUS_4_6_CORRECTED BIT(3) +#define NAND_STATUS_1_3_CORRECTED BIT(4) +#define NAND_STATUS_7_8_CORRECTED (BIT(4) | BIT(3)) struct nand_onfi_vendor_micron { u8 two_plane_read; @@ -137,18 +155,31 @@ micron_nand_read_page_on_die_ecc(struct mtd_info *mtd, struct nand_chip *chip, if (ret) goto out; - if (status & NAND_STATUS_FAIL) { + /* + * The internal ECC doesn't tell us the number of bitflips + * that have been corrected, but tells us if it recommends to + * rewrite the block. If it's the case, then we pretend we had + * a number of bitflips equal to the ECC strength, which will + * hint the NAND core to rewrite the block. + */ + switch (status & NAND_STATUS_MASK) { + case NAND_STATUS_UNCORRECTABLE: mtd->ecc_stats.failed++; - } else if (status & NAND_STATUS_WRITE_RECOMMENDED) { - /* - * The internal ECC doesn't tell us the number of bitflips - * that have been corrected, but tells us if it recommends to - * rewrite the block. If it's the case, then we pretend we had - * a number of bitflips equal to the ECC strength, which will - * hint the NAND core to rewrite the block. - */ - mtd->ecc_stats.corrected += chip->ecc.strength; + break; + case NAND_STATUS_1_3_CORRECTED: + mtd->ecc_stats.corrected++; + max_bitflips = 1; + break; + case NAND_STATUS_4_6_CORRECTED: + mtd->ecc_stats.corrected += 4; + /* rewrite recommended */ + max_bitflips = chip->ecc.strength; + break; + case NAND_STATUS_7_8_CORRECTED: + mtd->ecc_stats.corrected += 7; + /* rewrite recommended */ max_bitflips = chip->ecc.strength; + break; } ret = nand_read_data_op(chip, buf, mtd->writesize, false); @@ -239,13 +270,6 @@ static int micron_supports_on_die_ecc(struct nand_chip *chip) if (feature[0] & ONFI_FEATURE_ON_DIE_ECC_EN) return MICRON_ON_DIE_MANDATORY; - /* - * Some Micron NANDs have an on-die ECC of 4/512, some other - * 8/512. We only support the former. - */ - if (chip->ecc_strength_ds != 4) - return MICRON_ON_DIE_UNSUPPORTED; - return MICRON_ON_DIE_SUPPORTED; } @@ -275,9 +299,9 @@ static int micron_nand_init(struct nand_chip *chip) return -EINVAL; } - chip->ecc.bytes = 8; + chip->ecc.bytes = chip->ecc_strength_ds * 2; chip->ecc.size = 512; - chip->ecc.strength = 4; + chip->ecc.strength = chip->ecc_strength_ds; chip->ecc.algo = NAND_ECC_BCH; chip->ecc.read_page = micron_nand_read_page_on_die_ecc; chip->ecc.write_page = micron_nand_write_page_on_die_ecc; -- 2.17.1
