Hi Tokunori,
ikegami.t@xxxxxxxxx wrote on Thu, 17 Mar 2022 00:54:53 +0900:
> This is a preparation patch for the functional change in preparation to a change
> expected to fix the buffered writes on S29GL064N.
This is a preparation patch for the S29GL064N buffer writes fix. There
is no functional change.
>
> Fixes: dfeae1073583("mtd: cfi_cmdset_0002: Change write buffer to check correct value")
> Signed-off-by: Tokunori Ikegami <ikegami.t@xxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> ---
> drivers/mtd/chips/cfi_cmdset_0002.c | 77 ++++++++++++-----------------
> 1 file changed, 32 insertions(+), 45 deletions(-)
>
> diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c
> index a761134fd3be..e68ddf0f7fc0 100644
> --- a/drivers/mtd/chips/cfi_cmdset_0002.c
> +++ b/drivers/mtd/chips/cfi_cmdset_0002.c
> @@ -801,22 +801,12 @@ static struct mtd_info *cfi_amdstd_setup(struct mtd_info *mtd)
> return NULL;
> }
>
> -/*
> - * Return true if the chip is ready.
> - *
> - * Ready is one of: read mode, query mode, erase-suspend-read mode (in any
> - * non-suspended sector) and is indicated by no toggle bits toggling.
> - *
> - * Note that anything more complicated than checking if no bits are toggling
> - * (including checking DQ5 for an error status) is tricky to get working
> - * correctly and is therefore not done (particularly with interleaved chips
> - * as each chip must be checked independently of the others).
> - */
> -static int __xipram chip_ready(struct map_info *map, struct flchip *chip,
> - unsigned long addr)
> +static int __xipram chip_check(struct map_info *map, struct flchip *chip,
> + unsigned long addr, map_word *expected)
> {
> struct cfi_private *cfi = map->fldrv_priv;
> - map_word d, t;
> + map_word oldd, curd;
> + int ret;
>
> if (cfi_use_status_reg(cfi)) {
> map_word ready = CMD(CFI_SR_DRB);
> @@ -826,17 +816,35 @@ static int __xipram chip_ready(struct map_info *map, struct flchip *chip,
> */
> cfi_send_gen_cmd(0x70, cfi->addr_unlock1, chip->start, map, cfi,
> cfi->device_type, NULL);
> - d = map_read(map, addr);
> + curd = map_read(map, addr);
>
> - return map_word_andequal(map, d, ready, ready);
> + return map_word_andequal(map, curd, ready, ready);
A lot of the diff is just a rename. I am not against a rename if you
feel it's better, but in this order:
1: prepare the fix
2: fix
3: rename/define id's, whatever
> }
>
> - d = map_read(map, addr);
> - t = map_read(map, addr);
> + oldd = map_read(map, addr);
> + curd = map_read(map, addr);
> +
> + ret = map_word_equal(map, oldd, curd);
>
> - return map_word_equal(map, d, t);
> + if (!ret || !expected)
> + return ret;
> +
> + return map_word_equal(map, curd, *expected);
> }
>
> +/*
> + * Return true if the chip is ready.
> + *
> + * Ready is one of: read mode, query mode, erase-suspend-read mode (in any
> + * non-suspended sector) and is indicated by no toggle bits toggling.
> + *
> + * Note that anything more complicated than checking if no bits are toggling
> + * (including checking DQ5 for an error status) is tricky to get working
> + * correctly and is therefore not done (particularly with interleaved chips
> + * as each chip must be checked independently of the others).
> + */
> +#define chip_ready(map, chip, addr) chip_check(map, chip, addr, NULL)
I don't see the point of such a define. Just get rid of it.
> +
> /*
> * Return true if the chip is ready and has the correct value.
> *
> @@ -852,32 +860,11 @@ static int __xipram chip_ready(struct map_info *map, struct flchip *chip,
> * as each chip must be checked independently of the others).
> *
> */
> -static int __xipram chip_good(struct map_info *map, struct flchip *chip,
> - unsigned long addr, map_word expected)
> -{
> - struct cfi_private *cfi = map->fldrv_priv;
> - map_word oldd, curd;
> -
> - if (cfi_use_status_reg(cfi)) {
> - map_word ready = CMD(CFI_SR_DRB);
> -
> - /*
> - * For chips that support status register, check device
> - * ready bit
> - */
> - cfi_send_gen_cmd(0x70, cfi->addr_unlock1, chip->start, map, cfi,
> - cfi->device_type, NULL);
> - curd = map_read(map, addr);
> -
> - return map_word_andequal(map, curd, ready, ready);
> - }
> -
> - oldd = map_read(map, addr);
> - curd = map_read(map, addr);
> -
> - return map_word_equal(map, oldd, curd) &&
> - map_word_equal(map, curd, expected);
> -}
> +#define chip_good(map, chip, addr, expected) \
> + ({ \
> + map_word datum = expected; \
> + chip_check(map, chip, addr, &datum); \
> + })
What is this for? Same here, I don't see the point. Please get rid of
all these unnecessary helpers which do nothing, besides complicating
user's life.
> static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr, int mode)
> {
Thanks,
Miquèl
