porting marvell-nand driver for u-boot

[Miquel Raynal <miquel.raynal@bootlin.com>]

Hi Zak,

Zak Hays <zak.hays@lexmark.com> wrote on Mon, 9 Mar 2020 14:27:15 +0000:

> Hi Miqu?l,
> 
> Thanks for the quick response!
> 
> >Hi Zak,
> >
> >Zak Hays <zak.hays@lexmark.com> wrote on Thu, 5 Mar 2020 19:09:54 +0000:
> >  
> >> Hello all!
> >>
> >> I've recently run into an issue where I have enabled on-die ECC in Linux which required the block sizing I had been using to change from 2048 to 512. This is now causing UBI to throw the following error:  
> >
> >You know that you cannot do that and keep the content of your NAND
> >device right? You are basically enabling subpage access and UBI does
> >not support subpage changes.  
> 
> Yes, I am aware of this and have other plans to save away the contents
> of the NAND device and rewrite with the new block sizing.
> 
> >Otherwise, I think subpage access are supported by the pxa driver.  
> 
> Can you clarify this a little more? It looks like the u-boot pxa
> driver sets the NAND_NO_SUBPAGE_WRITE option by default in
> alloc_nand_resource(). That decides the value of mtd->subpage_sft in
> nand_base which ultimately leads to the UBI error I get below. Does
> the NO_SUBPAGE_WRITE automatically imply that SUBPAGE_READ is not
> allowed as well? Is there some other way to bypass this flag?

I think subpage_read are still allowed if the NAND part supports it.
But anyway, if they are enabled in Linux, they should be enabled in
U-Boot otherwise UBI will complain I suppose...

Thanks,
Miqu?l