brcmnand (iproc): bitflips and ECC errors due to ignored ECC config

[Rafał Miłecki]

On 25 January 2016 at 13:59, Rafał Miłecki <zajec5 at gmail.com> wrote:
> I've a D-Link DIR-885L router with following NAND:
> nand: device found, Manufacturer ID: 0x01, Chip ID: 0xf1
> nand: AMD/Spansion NAND 128MiB 3,3V 8-bit
> nand: 128 MiB, SLC, erase size: 128 KiB, page size: 2048, OOB size: 64
>
> It uses ECC strength 1 with step size 512 so I created DT with:
> nand-ecc-strength = <1>;
> nand-ecc-step-size = <512>;
>
> Unfortunately all I get from mtd_read are -EUCLEAN (6%) and -EBADMSG
> (94%) errors. It's becase of the following code in brcmnand_setup_dev:
> if (chip->ecc.strength == 1) /* Hamming */
> cfg->ecc_level = 15;
>
> After removing this special handling of strength 1 I can use my NAND
> as expected.
>
> Is there a good reason for this hamming condition? Can we add some way
> of using strength 1?

Ping?

-- 
Rafał