Re: [PATCH] mtd: rawnand: onfi: read parameter pages in one go

Miquel Raynal
2024-05-16T13:09:34Z

Hi Sascha,

> > > > nand_read_data_op() is not supported by all NAND controllers.
> > > > nand_change_read_column_op() is not supported or at least is hard to
> > > > support by NAND controllers that use a different page layout than
> > > > expected by the NAND core.
> > >
> > > I'm sorry but RNDOUT is not so hard to support, and I know no NAND
> > > controller without this feature (I think even the first mxc controller
> > > supports it?). However, the command does not exist on small page NANDs
> > > (512 bytes).
> >
> > Nevermind, the ONFI spec (in all versions) states that RNDOUT are
> > allowed during parameter page reads, regardless of the size of the chip
> > (at least, that is not mentioned).
>
> I could imagine that there are no ONFI compliant chips with small pages,
> I don't know how to verify this though.
>
> Anyway, this was a try to make reading the parameter pages a bit more
> straight forward. It seems the MXC NAND controller can't support reading
> three parameter pages in one go either. It works in software ECC mode
> because I reverse the syndome type layout the controller introduces, but
> it can't work with hardware ECC.

Hardware ECC should not be used at this step and should be disabled.
There should not be any ECC interference.

> So disregard this patch.

I now have a proposal, I'll send a v2 of my previous series.