Re: [PATCH v4 2/9] mtd: nand: make sure mtd_oob_ops consistent in bbt

[Boris Brezillon <boris.brezillon@free-electrons.com>]

On Thu, 23 Mar 2017 17:43:39 +0800
Peter Pan <peterpandong@micron.com> wrote:

> This commit makes sure struct mtd_oob_ops passed to mtd_read/write_ops()
> is consistent, which means .datbuf = NULL and .len = 0 when not reading
> page; .oobbuf = NULL and .ooblen = 0 when not reading oob. If no, (ie.
> ops.datbuf = NULL, while ops.len != 0.), nand_for_each_page() will run
> forever.
> 
> Signed-off-by: Peter Pan <peterpandong@micron.com>
> ---
>  drivers/mtd/nand/bbt.c | 13 ++++++-------
>  1 file changed, 6 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/mtd/nand/bbt.c b/drivers/mtd/nand/bbt.c
> index 94cd3e5..c35a6e8 100644
> --- a/drivers/mtd/nand/bbt.c
> +++ b/drivers/mtd/nand/bbt.c
> @@ -328,7 +328,7 @@ static int scan_read_oob(struct nand_device *this, uint8_t *buf, loff_t offs,
>  			 size_t len)
>  {
>  	struct mtd_info *mtd = nand_to_mtd(this);
> -	struct mtd_oob_ops ops;
> +	struct mtd_oob_ops ops = {0};

	struct mtd_oob_ops ops = { };

>  	int res, ret = 0;
>  
>  	ops.mode = MTD_OPS_PLACE_OOB;
> @@ -369,11 +369,12 @@ static int scan_write_bbt(struct nand_device *this, loff_t offs, size_t len,
>  			  uint8_t *buf, uint8_t *oob)
>  {
>  	struct mtd_info *mtd = nand_to_mtd(this);
> -	struct mtd_oob_ops ops;
> +	struct mtd_oob_ops ops = {0};
>  
>  	ops.mode = MTD_OPS_PLACE_OOB;
>  	ops.ooboffs = 0;
> -	ops.ooblen = nand_per_page_oobsize(this);
> +	/* oob from caller may be NULL */
> +	ops.ooblen = oob ? nand_per_page_oobsize(this) : 0;
>  	ops.datbuf = buf;
>  	ops.oobbuf = oob;
>  	ops.len = len;
> @@ -428,13 +429,12 @@ static int scan_block_fast(struct nand_device *this, struct nand_bbt_descr *bd,
>  			   loff_t offs, uint8_t *buf, int numpages)
>  {
>  	struct mtd_info *mtd = nand_to_mtd(this);
> -	struct mtd_oob_ops ops;
> +	struct mtd_oob_ops ops = {0};
>  	int j, ret;
>  
>  	ops.ooblen = nand_per_page_oobsize(this);
>  	ops.oobbuf = buf;
>  	ops.ooboffs = 0;
> -	ops.datbuf = NULL;
>  	ops.mode = MTD_OPS_PLACE_OOB;
>  
>  	for (j = 0; j < numpages; j++) {
> @@ -734,11 +734,10 @@ static int write_bbt(struct nand_device *this, uint8_t *buf,
>  	uint8_t rcode = td->reserved_block_code;
>  	size_t retlen, len = 0;
>  	loff_t to;
> -	struct mtd_oob_ops ops;
> +	struct mtd_oob_ops ops = {0};
>  
>  	ops.ooblen = nand_per_page_oobsize(this);
>  	ops.ooboffs = 0;
> -	ops.datbuf = NULL;
>  	ops.mode = MTD_OPS_PLACE_OOB;
>  
>  	if (!rcode)