diff options
| -rw-r--r-- | drivers/mtd/nand/gpmi-nand/gpmi-nand.c | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c index 21f3c551a919..f1ad1696b549 100644 --- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c +++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c @@ -1035,6 +1035,61 @@ static void block_mark_swapping(struct gpmi_nand_data *this, p[1] = (p[1] & mask) | (from_oob >> (8 - bit)); } +static bool gpmi_erased_check(struct gpmi_nand_data *this, + unsigned char *data, unsigned int chunk, int page, + unsigned int *max_bitflips) +{ + struct nand_chip *chip = &this->nand; + struct mtd_info *mtd = &this->mtd; + struct bch_geometry *geo = &this->bch_geometry; + int base = geo->ecc_chunkn_size * chunk; + unsigned int flip_bits = 0, flip_bits_noecc = 0; + uint64_t *buf = (uint64_t *)this->data_buffer_dma; + unsigned int threshold; + int i; + + threshold = geo->gf_len / 2; + if (threshold > geo->ecc_strength) + threshold = geo->ecc_strength; + + /* Count bitflips */ + for (i = 0; i < geo->ecc_chunkn_size; i++) { + flip_bits += hweight8(~data[base + i]); + if (flip_bits > threshold) + return false; + } + + /* + * Read out the whole page with ECC disabled, and check it again, + * This is more strict then just read out a chunk, and it makes + * the code more simple. + */ + chip->cmdfunc(mtd, NAND_CMD_READ0, 0, page); + chip->read_buf(mtd, (uint8_t *)buf, mtd->writesize); + + /* Count the bitflips for the no ECC buffer */ + for (i = 0; i < mtd->writesize / 8; i++) { + flip_bits_noecc += hweight64(~buf[i]); + if (flip_bits_noecc > threshold) + return false; + } + + /* Tell the upper layer the bitflips we corrected. */ + mtd->ecc_stats.corrected += flip_bits; + *max_bitflips = max_t(unsigned int, *max_bitflips, flip_bits); + + /* + * The geo->payload_size maybe not equal to the page size + * when the Subpage-Read is enabled. + */ + memset(data, 0xff, geo->payload_size); + + dev_dbg(this->dev, "The page(%d) is an erased page(%d,%d,%d,%d).\n", + page, chunk, threshold, flip_bits, flip_bits_noecc); + + return true; +} + static int gpmi_ecc_read_page(struct mtd_info *mtd, struct nand_chip *chip, uint8_t *buf, int oob_required, int page) { @@ -1094,6 +1149,9 @@ static int gpmi_ecc_read_page(struct mtd_info *mtd, struct nand_chip *chip, } if (*status == STATUS_UNCORRECTABLE) { + if (gpmi_erased_check(this, payload_virt, i, + page, &max_bitflips)) + break; mtd->ecc_stats.failed++; continue; } |