diff options
| -rw-r--r-- | drivers/mtd/nand/mxs_nand.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/drivers/mtd/nand/mxs_nand.c b/drivers/mtd/nand/mxs_nand.c index 5bba8c5..1e93e5f 100644 --- a/drivers/mtd/nand/mxs_nand.c +++ b/drivers/mtd/nand/mxs_nand.c @@ -639,6 +639,45 @@ static uint8_t mxs_nand_read_byte(struct mtd_info *mtd) return buf; } +static bool mxs_nand_erased_page(struct mtd_info *mtd, struct nand_chip *nand, + uint8_t *buf, int chunk, int page) +{ + int gf_len = galois_field; + unsigned int flip_bits = 0, flip_bits_noecc = 0; + unsigned int threshold; + unsigned int ecc_chunkn_size = MXS_NAND_CHUNK_DATA_CHUNK_SIZE; + unsigned int base = ecc_chunkn_size * chunk; + uint32_t *dma_buf = (uint32_t *)buf; + int i; + + threshold = gf_len / 2; + if (threshold > ecc_strength) + threshold = ecc_strength; + + for (i = 0; i < ecc_chunkn_size; i++) { + flip_bits += hweight8(~buf[base + i]); + if (flip_bits > threshold) + return false; + } + + nand->cmdfunc(mtd, NAND_CMD_READ0, 0, page); + nand->read_buf(mtd, buf, mtd->writesize); + + for (i = 0; i < mtd->writesize / 4; i++) { + flip_bits_noecc += hweight32(~dma_buf[i]); + if (flip_bits_noecc > threshold) + return false; + } + + mtd->ecc_stats.corrected += flip_bits; + + memset(buf, 0xff, mtd->writesize); + + printf("The page(%d) is an erased page(%d,%d,%d,%d).\n", page, chunk, threshold, flip_bits, flip_bits_noecc); + + return true; +} + /* * Read a page from NAND. */ @@ -741,6 +780,8 @@ static int mxs_nand_ecc_read_page(struct mtd_info *mtd, struct nand_chip *nand, goto rtn; } + mxs_nand_return_dma_descs(nand_info); + /* Invalidate caches */ mxs_nand_inval_data_buf(nand_info); @@ -757,6 +798,9 @@ static int mxs_nand_ecc_read_page(struct mtd_info *mtd, struct nand_chip *nand, continue; if (status[i] == 0xfe) { + if (mxs_nand_erased_page(mtd, nand, + nand_info->data_buf, i, page)) + break; failed++; continue; } |