[U-Boot] [PATCH v3 07/11] mtd: nand: add Faraday FTNANDC021 NAND controller support

Kuo-Jung Su
2013-04-30T01:33:03Z

2013/4/30 Scott Wood <scottwood@freescale.com>:
> On 04/28/2013 10:28:14 PM, Kuo-Jung Su wrote:
>>
>> 2013/4/27 Scott Wood <scottwood@freescale.com>:
>>
>> > Shouldn't .eccpos depend on HWECC?
>> >
>> >
>>
>> Actually it means nothing here, the ECC function is designed to be some
>> kind of
>> a blackbox to users (i.e softwares), the actual position of ECC codes
>> are not documented
>> in the datasheet, I have to dig it out from RTL which I do not have
>> permission to access.
>
>
> Maybe get rid of .eccpos altogether, and supply your own (much simpler)
> hwecc read/write_page functions -- similar to what fsl_elbc_nand, which also
> has transparent (but not hidden) ECC, does? This would also let you get rid
> of hwctl/calculate/correct.
>
>

Got it, thanks
I'll check it later.

>> > Is it really all in one step, regardless of page size?
>> >
>>
>> Theoretical, NO.
>> It uses R-S or BCH for Forwarding Error Correction, which is selected
>> at RTL level.
>> Which means it actually 522 bytes per step at RS and 528 bytes per step at
>> BCH.
>>
>> However it's all blackbox to software, the FTNANDC021 simply supports only
>> page read, so looks like everything is done at 1 step.
>
>
> It would matter if you could detect correctable errors, but since you can't,
> it doesn't.
>

Got it, thanks

> -Scott

--
Best wishes,
Kuo-Jung Su