Re: [PATCH v2 06/12] mtd: nand_bbt: use erase() and is_bad_bbm() hook in BBT

From: Boris Brezillon
Date: Wed Jan 06 2016 - 08:49:23 EST


On Tue, 15 Dec 2015 05:59:32 +0000
Peter Pan <peterpansjtu@xxxxxxxxx> wrote:

> From: Brian Norris <computersforpeace@xxxxxxxxx>
>
> Since NAND already create its nand_bbt struct, we can use erase()
> hook instead of call nand_erase_nand() directly. Also, we can use
> is_bad_bbm() to avoid passing badblock_pattern to BBT.
>
> Signed-off-by: Brian Norris <computersforpeace@xxxxxxxxx>
> [Peter: remove @buf in create_bbt()]
> Signed-off-by: Peter Pan <peterpandong@xxxxxxxxxx>
> ---
> drivers/mtd/nand/nand_bbt.c | 138 ++++----------------------------------------
> 1 file changed, 12 insertions(+), 126 deletions(-)
>
> diff --git a/drivers/mtd/nand/nand_bbt.c b/drivers/mtd/nand/nand_bbt.c
> index f256be1..a5c8ab5 100644
> --- a/drivers/mtd/nand/nand_bbt.c
> +++ b/drivers/mtd/nand/nand_bbt.c
> @@ -122,23 +122,6 @@ static int check_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_desc
> }

[...]

> /**
> * create_bbt - [GENERIC] Create a bad block table by scanning the device
> * @mtd: MTD device structure
> - * @buf: temporary buffer
> - * @bd: descriptor for the good/bad block search pattern
> * @chip: create the table for a specific chip, -1 read all chips; applies only
> * if NAND_BBT_PERCHIP option is set
> *
> * Create a bad block table by scanning the device for the given good/bad block
> * identify pattern.
> */
> -static int create_bbt(struct mtd_info *mtd, uint8_t *buf,
> - struct nand_bbt_descr *bd, int chip)
> +static int create_bbt(struct mtd_info *mtd, int chip)
> {
> struct nand_chip *this = mtd_to_nand(mtd);
> - int i, numblocks, numpages;
> - int startblock;
> + int i, startblock, numblocks;
> loff_t from;
>
> pr_info("Scanning device for bad blocks\n");
>
> - if (bd->options & NAND_BBT_SCAN2NDPAGE)
> - numpages = 2;
> - else
> - numpages = 1;
> -
> if (chip == -1) {
> numblocks = mtd->size >> this->bbt_erase_shift;
> startblock = 0;
> @@ -482,15 +425,10 @@ static int create_bbt(struct mtd_info *mtd, uint8_t *buf,
> from = (loff_t)startblock << this->bbt_erase_shift;
> }
>
> - if (this->bbt_options & NAND_BBT_SCANLASTPAGE)
> - from += mtd->erasesize - (mtd->writesize * numpages);
> -
> for (i = startblock; i < numblocks; i++) {
> int ret;
>
> - BUG_ON(bd->options & NAND_BBT_NO_OOB);
> -
> - ret = scan_block_fast(mtd, bd, from, buf, numpages);
> + ret = this->nand_bbt->is_bad_bbm(mtd, from);

Same comment as for the previous patch: I think it would be safer to
create a wrapper function to do that.

> if (ret < 0)
> return ret;
>
> @@ -619,7 +557,6 @@ static int write_bbt(struct mtd_info *mtd, uint8_t *buf,
> int chipsel)
> {
> struct nand_chip *this = mtd_to_nand(mtd);
> - struct erase_info einfo;
> int i, res, chip = 0;
> int bits, startblock, dir, page, offs, numblocks, sft, sftmsk;
> int nrchips, pageoffs, ooboffs;
> @@ -782,11 +719,7 @@ static int write_bbt(struct mtd_info *mtd, uint8_t *buf,
> buf[offs + (i >> sft)] &= ~(msk[dat] << sftcnt);
> }
>
> - memset(&einfo, 0, sizeof(einfo));
> - einfo.mtd = mtd;
> - einfo.addr = to;
> - einfo.len = 1 << this->bbt_erase_shift;
> - res = nand_erase_nand(mtd, &einfo, 1);
> + res = this->nand_bbt->erase(mtd, to);

Ditto.





--
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
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