Re: [PATCH v1 4/5] mtd: rawnand: meson: clear OOB buffer before read

Richard Weinberger
2023-05-03T19:49:01Z

Sorry for joining the party late.

On Wed, May 3, 2023 at 10:07 AM Miquel Raynal <miquel.raynal@bootlin.com> wrote:
> > So for me main question here is:
> >
> > How JFFS2 should work with controllers where we can't update data and OOB
> > independently? Driver of this filesystem knows nothing about this features of
> > the controller.
> >
> > Or JFFS2 works incorrectly in my case when it tries to call write page callback
> > after calling write OOB callback (IIUC it is better to ask Richard as You mentioned above).
> >
> > Or may be it is better to suppress OOB write callback (or set it to NULL) in this
> > driver as in vendor's driver?
>
> I would assume using the unprotected free OOB bytes to store the
> cleanmarkers should work. But that's a bit fragile and very filesystem
> oriented. I don't like this much. But on the other side JFFS2 is
> legacy, you should use UBI (which does not play with OOB areas) :-)

Please note that JFFS2's main use case is NOR flash. Support for NAND
flash was never
considered as fully complete/stable. That's why UBIFS (JFFS3 in the
very beginning)
was invented.

Thanks,
//richard