Re: [PATCH 38/39] mtd: nand: denali: remove Toshiba, Hynix specific fixup code

From: Boris Brezillon
Date: Sun Nov 27 2016 - 11:29:09 EST


On Sun, 27 Nov 2016 03:06:24 +0900
Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> wrote:

> The Denali IP can automatically detect device parameters such as
> page size, device width, etc. and this driver currently relies on it.
> However, this hardware function is problematic.
>
> [1] Due to a hardware bug, various misdetected cases are known.
> That is why get_toshiba_nand_para(), get_hynix_nand_para() exist
> to fix the misdetected parameters. It is not realistic to add a
> new NAND device to the *black list* every time we are hit by a
> misdetected case. We would never be able to guarantee that all
> the cases are covered.
>
> [2] Because this feature is unreliable, it is disabled on some
> platforms.
>
> The nand_scan_ident() sets device parameters such as mtd->writesize,
> mtd->erasesize, etc. in a more tested way. We should not set the
> hardware registers in a different, unreliable way. Instead, set
> the parameters from nand_scan_ident() back to the registers.
>

Thanks a lot for fixing that.

> Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
> ---
>
> drivers/mtd/nand/denali.c | 39 ++++++---------------------------------
> 1 file changed, 6 insertions(+), 33 deletions(-)
>
> diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
> index df174ca..1aa19ec 100644
> --- a/drivers/mtd/nand/denali.c
> +++ b/drivers/mtd/nand/denali.c
> @@ -338,35 +338,6 @@ static void get_samsung_nand_para(struct denali_nand_info *denali, u8 device_id)
> }
> }
>
> -static void get_toshiba_nand_para(struct denali_nand_info *denali)
> -{
> - /*
> - * Workaround to fix a controller bug which reports a wrong
> - * spare area size for some kind of Toshiba NAND device
> - */
> - if ((ioread32(denali->flash_reg + DEVICE_MAIN_AREA_SIZE) == 4096) &&
> - (ioread32(denali->flash_reg + DEVICE_SPARE_AREA_SIZE) == 64))
> - iowrite32(216, denali->flash_reg + DEVICE_SPARE_AREA_SIZE);
> -}
> -
> -static void get_hynix_nand_para(struct denali_nand_info *denali, u8 device_id)
> -{
> - switch (device_id) {
> - case 0xD5: /* Hynix H27UAG8T2A, H27UBG8U5A or H27UCG8VFA */
> - case 0xD7: /* Hynix H27UDG8VEM, H27UCG8UDM or H27UCG8V5A */
> - iowrite32(128, denali->flash_reg + PAGES_PER_BLOCK);
> - iowrite32(4096, denali->flash_reg + DEVICE_MAIN_AREA_SIZE);
> - iowrite32(224, denali->flash_reg + DEVICE_SPARE_AREA_SIZE);
> - iowrite32(0, denali->flash_reg + DEVICE_WIDTH);
> - break;
> - default:
> - dev_warn(denali->dev,
> - "Unknown Hynix NAND (Device ID: 0x%x).\n"
> - "Will use default parameter values instead.\n",
> - device_id);
> - }
> -}
> -
> /*
> * determines how many NAND chips are connected to the controller. Note for
> * Intel CE4100 devices we don't support more than one device.
> @@ -468,10 +439,6 @@ static u16 denali_nand_timing_set(struct denali_nand_info *denali)
> return FAIL;
> } else if (maf_id == 0xEC) { /* Samsung NAND */
> get_samsung_nand_para(denali, device_id);
> - } else if (maf_id == 0x98) { /* Toshiba NAND */
> - get_toshiba_nand_para(denali);
> - } else if (maf_id == 0xAD) { /* Hynix NAND */
> - get_hynix_nand_para(denali, device_id);
> }
>
> dev_info(denali->dev,
> @@ -1661,6 +1628,12 @@ int denali_init(struct denali_nand_info *denali)
> chip->ecc.strength);
>
> iowrite32(chip->ecc.strength, denali->flash_reg + ECC_CORRECTION);
> + iowrite32(mtd->erasesize / mtd->writesize,
> + denali->flash_reg + PAGES_PER_BLOCK);
> + iowrite32(denali->nand.options & NAND_BUSWIDTH_16 ? 1 : 0,
> + denali->flash_reg + DEVICE_WIDTH);
> + iowrite32(mtd->writesize, denali->flash_reg + DEVICE_MAIN_AREA_SIZE);
> + iowrite32(mtd->oobsize, denali->flash_reg + DEVICE_SPARE_AREA_SIZE);
>
> mtd_set_ooblayout(mtd, &denali_ooblayout_ops);
>