[PATCH 2/3] mtd: nand: read (from DT) and store ECC algorithm

[Rafał Miłecki]

On 1 April 2016 at 18:07, Brian Norris <computersforpeace at gmail.com> wrote:
> On Fri, Feb 12, 2016 at 07:11:24PM +0100, Rafał Miłecki wrote:
>> This will allow drivers handle ECC properly.
>>
>> Signed-off-by: Rafał Miłecki <zajec5 at gmail.com>
>> ---
>>  drivers/mtd/nand/nand_base.c | 6 +++++-
>>  include/linux/mtd/nand.h     | 1 +
>>  2 files changed, 6 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
>> index f2c8ff3..ef977f3 100644
>> --- a/drivers/mtd/nand/nand_base.c
>> +++ b/drivers/mtd/nand/nand_base.c
>> @@ -3979,7 +3979,7 @@ ident_done:
>>  static int nand_dt_init(struct nand_chip *chip)
>>  {
>>       struct device_node *dn = nand_get_flash_node(chip);
>> -     int ecc_mode, ecc_strength, ecc_step;
>> +     int ecc_mode, ecc_algo, ecc_strength, ecc_step;
>>
>>       if (!dn)
>>               return 0;
>> @@ -3991,6 +3991,7 @@ static int nand_dt_init(struct nand_chip *chip)
>>               chip->bbt_options |= NAND_BBT_USE_FLASH;
>>
>>       ecc_mode = of_get_nand_ecc_mode(dn);
>> +     ecc_algo = of_get_nand_ecc_algo(dn);
>>       ecc_strength = of_get_nand_ecc_strength(dn);
>>       ecc_step = of_get_nand_ecc_step_size(dn);
>>
>> @@ -4003,6 +4004,9 @@ static int nand_dt_init(struct nand_chip *chip)
>>       if (ecc_mode >= 0)
>>               chip->ecc.mode = ecc_mode;
>>
>> +     if (ecc_algo >= 0)
>> +             chip->ecc.algo = ecc_algo;
>> +
>
> While this might appear to handle the absence of the nand-ecc-algo
> property correctly, this isn't safe. This means that any existing DT
> without the property will get treated as Hamming ECC. Perhaps we need
> the enum to have a 0 value of 'NAND_ECC_ALGO_UNKNOWN' or something like
> that?

You're commenting on an old series. If you take a look at:
https://patchwork.ozlabs.org/patch/601180/
that also got applied to the:
https://github.com/linux-nand/linux/commits/nand/next
repo, you'll see we have NAND_ECC_UNKNOWN there.