Get error -74 (ECC error) during ubiattach

[Oleksij Rempel]

Am 20.12.2014 um 11:12 schrieb Richard Weinberger:
> Am 20.12.2014 um 11:05 schrieb Oleksij Rempel:
>> Am 20.12.2014 um 11:02 schrieb Richard Weinberger:
>>> Am 20.12.2014 um 11:00 schrieb Oleksij Rempel:
>>>> Am 20.12.2014 um 10:27 schrieb Richard Weinberger:
>>>>> Hi!
>>>>>
>>>>> Am 20.12.2014 um 04:43 schrieb t kevin:
>>>>>> So for uncorrectable ECC error ( e.g., bad block) the only way out is
>>>>>> to do a fresh ubiformat?
>>>>>> For device like harddisk you get bad blocks all the time, if it is not
>>>>>> in the critical sector things can be fixed as much as possible by fsck
>>>>>> so I was looking for something like fsck.ubifs.
>>>>>
>>>>> An uncorrectable ECC error means that more bits flipped than your ECC
>>>>> algorithm can fix.
>>>>
>>>> At same time uncorrectable ECC error mean, the page was erase and there
>>>> is no ECC sum. Something should be written to create ECC.
>>>
>>> Which would be a driver bug and needs fixing.
>>
>> No at all. If driver get request to erase page, it should do it and
>> nothing more.
>> There are use cases where erase means erase, and not erase + write ecc.
> 
> Raw mode is a different thing.

There is no raw erase mode in this api.

>> It is not a driver bug!
> 
> If users on top of MTD read from an erased block it has to return 0xFF bytes and
> not an ECC error.
> IOW if mtd_erase() -> mtd_read() causes an ECC error with your driver it needs
> fixing.


check out this code:
https://github.com/olerem/linux-2.6/blob/uparm_9260-2014.12.17.1/drivers/mtd/nand/nand_base.c#L2686

This commands passed to flash chip. There is nothing about erase and
write ecc.

-- 
Regards,
Oleksij

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