[Yaffs] Re: Writing a single file marks entire device as bad

[Martin Egholm Nielsen]

>>>> Now, new strange things are happening!
>>>> I enabled "CONFIG_MTD_NAND_VERIFY_WRITE=y" in the kernel, and 
>>>> suddenly it begun working!!
>>>> However, I get these kernel messages (alot) whenever I try to 
>>>> read/write anything:
>>>>
>>>> === 8< 8< 8< ===
>>>>    Writing data without ECC to NAND-FLASH is not recommended
>>>>    Writing data without ECC to NAND-FLASH is not recommended
>>>>    Writing data without ECC to NAND-FLASH is not recommended
>>>>    Writing data without ECC to NAND-FLASH is not recommended
>>>>    Reading data from NAND FLASH without ECC is not recommended
>>>> Is there really no ECC running now? I thought that config-option for 
>>>> MTD did the job?
>>> You should only do this if yaffs is doing the ECC instead.
>> So, this is how I have the configuration in order to get it to work:
>>
>> YAFFS_USE_NANDECC=n
>> CONFIG_MTD_NAND_VERIFY_WRITE=y
>>
>> My questions now are then:
>> 1) Is there any ECC enabled now?
> 
> 
> I think it's not:
>   - yaffs' ECC is disabled (YAFFS_USE_NANDECC=n)
>   - from my understanding, the MTD ECC depend of your MTD NAND chip (the 
> field eccmode of nand_chip,
>     this value is set to NAND_ECC_NONE, NAND_ECC_SOFT, NAND_ECC_HW6_512, 
> ...)
>     You can only receive the message "Writing data without ECC to 
> NAND-FLASH is not recommended"
>     if eccmode is set to NAND_ECC_NONE.
> 
> What type of nand chip you use?
Samsung K9F5608U0C - 32Mx8...

> Have tried the options  CONFIG_MTD_NAND_VERIFY_WRITE=y && 
> YAFFS_USE_NANDECC=y ?
Yes... I started with;
CONFIG_USE_NANDECC=y
CONFIG_MTD_NAND_VERIFY_WRITE=n

that didn't work... Then I tried [y,y] - that didn't work either. And 
finally, I ended up with [n,y] - and got alot of whinging! :-)

// Martin