[PATCH 2/2] mtd: nand: Only allocate ecc->{calc, code}_buf when actually needed
Masahiro Yamada
yamada.masahiro at socionext.com
Tue Dec 5 07:29:07 PST 2017
2017-12-05 20:09 GMT+09:00 Boris Brezillon <boris.brezillon at free-electrons.com>:
> The only users of the ecc->{calc,code}_buf buffers are NAND controller
> drivers implementing ecc->calculate() and/or ecc->correct(). Since the
> ->oobsize can be non-negligle, especially on modern NAND devices, we'd
> better allocate it only when it is actually required.
>
> Make ecc->{calc,code}_buf allocation dependent on the presence of
> ecc->calculate() or ecc->correct().
>
> Signed-off-by: Boris Brezillon <boris.brezillon at free-electrons.com>
> ---
> drivers/mtd/nand/nand_base.c | 25 +++++++++++--------------
> 1 file changed, 11 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
> index 71e70c4964f3..e6873d10c574 100644
> --- a/drivers/mtd/nand/nand_base.c
> +++ b/drivers/mtd/nand/nand_base.c
> @@ -5318,21 +5318,9 @@ int nand_scan_tail(struct mtd_info *mtd)
> return -EINVAL;
> }
>
> - ecc->calc_buf = kmalloc(mtd->oobsize, GFP_KERNEL);
> - if (!ecc->calc_buf)
> - return -ENOMEM;
> -
> - ecc->code_buf = kmalloc(mtd->oobsize, GFP_KERNEL);
> - if (!ecc->code_buf) {
> - ret = -ENOMEM;
> - goto err_free_buf;
> - }
> -
> chip->data_buf = kmalloc(mtd->writesize + mtd->oobsize, GFP_KERNEL);
> - if (!chip->data_buf) {
> - ret = -ENOMEM;
> - goto err_free_buf;
> - }
> + if (!chip->data_buf)
> + return -ENOMEM;
>
> /*
> * FIXME: some NAND manufacturer drivers expect the first die to be
> @@ -5495,6 +5483,15 @@ int nand_scan_tail(struct mtd_info *mtd)
> goto err_nand_manuf_cleanup;
> }
>
> + if (ecc->correct || ecc->calculate) {
> + ecc->calc_buf = kmalloc(mtd->oobsize, GFP_KERNEL);
> + ecc->code_buf = kmalloc(mtd->oobsize, GFP_KERNEL);
> + if (!ecc->calc_buf || !ecc->code_buf) {
> + ret = -ENOMEM;
> + goto err_nand_manuf_cleanup;
> + }
> + }
> +
> /* For many systems, the standard OOB write also works for raw */
> if (!ecc->read_oob_raw)
> ecc->read_oob_raw = ecc->read_oob;
> --
> 2.11.0
I wondered if chip->data_buf allocation could be moved as well,
but otherwise, looks good to me.
Reviewed-by: Masahiro Yamada <yamada.masahiro at socionext.com>
--
Best Regards
Masahiro Yamada
More information about the linux-mtd
mailing list