[U-Boot] [PATCH 5/5] NAND: Add scrub.quiet command option

Scott Wood
2011-09-12T23:24:22Z

On 09/12/2011 02:42 PM, Marek Vasut wrote:
> On Monday, September 12, 2011 09:36:49 PM Scott Wood wrote:
>> On 09/12/2011 02:28 PM, Marek Vasut wrote:
>>> On Monday, September 12, 2011 09:19:06 PM Scott Wood wrote:
>>>> What's it doing with them? Migrating them is something that should only
>>>> happen on the first use, as there will later be data in the factory bad
>>>> block area, right? So it shouldn't be "always". Migration should be an
>>>> explicitly requested option. Like scrub. :-)
>>>>
>>>> Where is the code that does this? Which driver?
>>>
>>> The BCH accelerator does this.
>>
>> In hardware? What chip is this, and where is the code that drives this
>> chip?
>
> I think it does something to it, yes. i.MX287, see the patchset [PATCH 00/15 V2]
> Support for the DENX M28 SoM, [PATCH 09/15] iMX28: Add GPMI NAND driver .

I looked at the code and the datasheet, and without getting into it too
deeply, I don't see how BCH is involved in an erase operation. What
specifically are you seeing happen?

The "Raw NAND Boot Mode" section (12.12 in my copy of the i.MX28 manual)
says that it uses BCH for ECC -- is this not the case? Is it some
special configuration of BCH?

I tried reading the "Bad Block Handling in the ROM" section and got a
headache.

I work for the PowerPC side of Freescale, in case you're wondering why
I'm unfamiliar with this. :-)

-Scott