From dbfc671856b349d702d94ccb96d38569991122cf Mon Sep 17 00:00:00 2001 From: Miquel Raynal Date: Thu, 19 Jul 2018 16:54:23 +0200 Subject: [PATCH] mtd: rawnand: marvell: rework BCH engine failure path We are about to support a new layout that triggers a faulty mechanism in BCH engine that creates bitflips in erased pages. Before adding the quirk that will workaround this issue, this patch just reworks a bit the section that handles ECC failures in BCH read path. Signed-off-by: Miquel Raynal Reviewed-by: Boris Brezillon --- drivers/mtd/nand/raw/marvell_nand.c | 73 +++++++++++++++++------------ 1 file changed, 42 insertions(+), 31 deletions(-) diff --git a/drivers/mtd/nand/raw/marvell_nand.c b/drivers/mtd/nand/raw/marvell_nand.c index 22481e9bfefc..a08858cca804 100644 --- a/drivers/mtd/nand/raw/marvell_nand.c +++ b/drivers/mtd/nand/raw/marvell_nand.c @@ -1295,11 +1295,11 @@ static int marvell_nfc_hw_ecc_bch_read_page(struct nand_chip *chip, { struct mtd_info *mtd = nand_to_mtd(chip); const struct marvell_hw_ecc_layout *lt = to_marvell_nand(chip)->layout; - int data_len = lt->data_bytes, spare_len = lt->spare_bytes, ecc_len; - u8 *data = buf, *spare = chip->oob_poi, *ecc; + int data_len = lt->data_bytes, spare_len = lt->spare_bytes; + u8 *data = buf, *spare = chip->oob_poi; int max_bitflips = 0; u32 failure_mask = 0; - int chunk, ecc_offset_in_page, ret; + int chunk, ret; /* * With BCH, OOB is not fully used (and thus not read entirely), not @@ -1340,46 +1340,57 @@ static int marvell_nfc_hw_ecc_bch_read_page(struct nand_chip *chip, * the controller in normal mode and must be re-read in raw mode. To * avoid dropping the performances, we prefer not to include them. The * user should re-read the page in raw mode if ECC bytes are required. + */ + + /* + * In case there is any subpage read error reported by ->correct(), we + * usually re-read only ECC bytes in raw mode and check if the whole + * page is empty. In this case, it is normal that the ECC check failed + * and we just ignore the error. * * However, for any subpage read error reported by ->correct(), the ECC * bytes must be read in raw mode and the full subpage must be checked * to see if it is entirely empty of if there was an actual error. */ for (chunk = 0; chunk < lt->nchunks; chunk++) { + int data_off_in_page, spare_off_in_page, ecc_off_in_page; + int data_off, spare_off, ecc_off; + int data_len, spare_len, ecc_len; + /* No failure reported for this chunk, move to the next one */ if (!(failure_mask & BIT(chunk))) continue; - /* Derive ECC bytes positions (in page/buffer) and length */ - ecc = chip->oob_poi + - (lt->full_chunk_cnt * lt->spare_bytes) + - lt->last_spare_bytes + - (chunk * ALIGN(lt->ecc_bytes, 32)); - ecc_offset_in_page = - (chunk * (lt->data_bytes + lt->spare_bytes + - lt->ecc_bytes)) + - (chunk < lt->full_chunk_cnt ? - lt->data_bytes + lt->spare_bytes : - lt->last_data_bytes + lt->last_spare_bytes); - ecc_len = chunk < lt->full_chunk_cnt ? - lt->ecc_bytes : lt->last_ecc_bytes; - - /* Do the actual raw read of the ECC bytes */ - nand_change_read_column_op(chip, ecc_offset_in_page, - ecc, ecc_len, false); - - /* Derive data/spare bytes positions (in buffer) and length */ - data = buf + (chunk * lt->data_bytes); - data_len = chunk < lt->full_chunk_cnt ? - lt->data_bytes : lt->last_data_bytes; - spare = chip->oob_poi + (chunk * (lt->spare_bytes + - lt->ecc_bytes)); - spare_len = chunk < lt->full_chunk_cnt ? - lt->spare_bytes : lt->last_spare_bytes; + data_off_in_page = chunk * (lt->data_bytes + lt->spare_bytes + + lt->ecc_bytes); + spare_off_in_page = data_off_in_page + + (chunk < lt->full_chunk_cnt ? lt->data_bytes : + lt->last_data_bytes); + ecc_off_in_page = spare_off_in_page + + (chunk < lt->full_chunk_cnt ? lt->spare_bytes : + lt->last_spare_bytes); + + data_off = chunk * lt->data_bytes; + spare_off = chunk * lt->spare_bytes; + ecc_off = (lt->full_chunk_cnt * lt->spare_bytes) + + lt->last_spare_bytes + + (chunk * (lt->ecc_bytes + 2)); + + data_len = chunk < lt->full_chunk_cnt ? lt->data_bytes : + lt->last_data_bytes; + spare_len = chunk < lt->full_chunk_cnt ? lt->spare_bytes : + lt->last_spare_bytes; + ecc_len = chunk < lt->full_chunk_cnt ? lt->ecc_bytes : + lt->last_ecc_bytes; + + nand_change_read_column_op(chip, ecc_off_in_page, + chip->oob_poi + ecc_off, ecc_len, + false); /* Check the entire chunk (data + spare + ecc) for emptyness */ - marvell_nfc_check_empty_chunk(chip, data, data_len, spare, - spare_len, ecc, ecc_len, + marvell_nfc_check_empty_chunk(chip, buf + data_off, data_len, + chip->oob_poi + spare_off, spare_len, + chip->oob_poi + ecc_off, ecc_len, &max_bitflips); } -- 2.45.2