diff options
| -rw-r--r-- | drivers/mtd/nand/raw/mxs_nand.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/drivers/mtd/nand/raw/mxs_nand.c b/drivers/mtd/nand/raw/mxs_nand.c index 3247064c3f..55d24cd062 100644 --- a/drivers/mtd/nand/raw/mxs_nand.c +++ b/drivers/mtd/nand/raw/mxs_nand.c @@ -612,6 +612,45 @@ 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, + u8 *buf, int chunk, int page) +{ + struct mxs_nand_info *nand_info = nand_get_controller_data(nand); + struct bch_geometry *geo = &nand_info->bch_geometry; + unsigned int flip_bits = 0, flip_bits_noecc = 0; + unsigned int threshold; + unsigned int base = geo->ecc_chunkn_size * chunk; + u32 *dma_buf = (u32 *)buf; + int i; + + threshold = geo->gf_len / 2; + if (threshold > geo->ecc_strength) + threshold = geo->ecc_strength; + + for (i = 0; i < geo->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. */ @@ -715,6 +754,8 @@ 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); @@ -731,6 +772,9 @@ 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; } |