Re: [EXT] Re: [PATCH] mtd: spinand: micron: add support for MT29F1G01AAADD

[Miquel Raynal <miquel.raynal@xxxxxxxxxxx>]

Hi Marco,

Marco Felsch <m.felsch@xxxxxxxxxxxxxx> wrote on Wed, 21 Aug 2019
09:19:14 +0200:

> Hi Shivamurthy, Miquel,
> 
> On 19-08-20 11:33, Shivamurthy Shastri (sshivamurthy) wrote:
> > Hi Marco,  
> 
> [ ... ]
> 
> > > > Okay. Just one last question. What is the common way to go to specify
> > > > the free area? By this I mean that the NAND has two areas to store the
> > > > user metadata calling it 'user metadata I' and 'user metadata II'. 'user
> > > > metadata II' isn't ecc protected so I skip them. But the current
> > > > supported chip does not skip the user metadata area which isn't
> > > > protected [1] table 10.
> > > >
> > > > [1] https://www.micron.com/~/media/documents/products/data-
> > > > sheet/nand-flash/70-series/m79a_2gb_3v_nand_spi.pdf  
> 
> @Miquel
> Do you can me help with that?

The xxx_ooblayout_free/ecc helpers are here for that. Section is the
number of distinct chunks you have in the OOB. If you have two chunks
but (metadata I and II) but you don't want to expose the unprotected
bytes, then just hide metadata II with a

if (section)
       return -ERANGE


Does this answer your question?

> 
> > > 
> > > I have written patch to make helpers to be more generic.
> > > They work for Micron's M78A, M79A and M70A series SPI NANDs.
> > >   
> > 
> > I missed link in last email, here it is.
> > 
> > http://patchwork.ozlabs.org/patch/1134724/  
> 
> This patch seem not to address my ooblayout.. So my patch is still
> needed.
> 
> Regards,
>   Marco
> 

Thanks,
Miquèl

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