[PATCH 2/7] mtd/nand: try to erase bad blocks only if scrub flag is provided

[Michael Nazzareno Trimarchi]

On Thu, Oct 6, 2022 at 5:52 PM Mikhail Kshevetskiy
<mikhail.kshevetskiy at iopsys.eu> wrote:
>
> On Thu, 6 Oct 2022 08:56:08 +0200
> Michael Nazzareno Trimarchi <michael at amarulasolutions.com> wrote:
>
> > [External email]
> >
> >
> >
> >
> >
> > Hi
> >
> > On Thu, Oct 6, 2022 at 5:15 AM <mikhail.kshevetskiy at iopsys.eu> wrote:
> > >
> > > From: Mikhail Kshevetskiy <mikhail.kshevetskiy at iopsys.eu>
> > >
> > > 'mtd erase' command should not erase bad blocks. To force bad block erasing
> > > there is 'mtd erase.dontskipbad' command (this command sets 'scrub' flag
> > > to true in the erase_info structure). Unfortunately nand layer ignore
> > > scrub flag and try to erases bad blocks unconditionally. This is wrong.
> > >
> > > Add checks to allow bad block erasing only if scrub flag is set.
> > >
> > > Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy at iopsys.eu>
> > > ---
> > >  drivers/mtd/nand/core.c | 5 ++++-
> > >  1 file changed, 4 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/mtd/nand/core.c b/drivers/mtd/nand/core.c
> > > index 99c29670c7..a4fb7602c9 100644
> > > --- a/drivers/mtd/nand/core.c
> > > +++ b/drivers/mtd/nand/core.c
> > > @@ -174,7 +174,10 @@ int nanddev_mtd_erase(struct mtd_info *mtd, struct
> > > erase_info *einfo) nanddev_offs_to_pos(nand, einfo->addr + einfo->len - 1,
> > > &last); while (nanddev_pos_cmp(&pos, &last) <= 0) {
> > >                 schedule();
> > > -               ret = nanddev_erase(nand, &pos);
> > > +               if (!einfo->scrub && nanddev_isbad(nand, &pos))
> >
> > The nandev_erase already check it here:
> >
> > if (nanddev_isbad(nand, pos) || nanddev_isreserved(nand, pos)) {
> >
>
> no it does not work. see nanddev_erase() code
>

Let me re-formulate it. What execution path are you taking into account?

The nand are erased using the cmd/nand interface and the erase command
there calls nand_erase_opts that take in account it.

Michael



The nand is erased using the
> if block is bad or reserverved, than warning is printed, than block is erased.
>
>
> > > +                       ret = -EIO;
> > > +               else
> > > +                       ret = nanddev_erase(nand, &pos);
> >
> > erase opt should already take in account scrub.
> >
> > Please extend the problem
> >
> > Michael
> > >                 if (ret) {
> > >                         einfo->fail_addr = nanddev_pos_to_offs(nand, &pos);
> > >
> > > --
> > > 2.35.1
> > >
> >
> >
> > --
> > Michael Nazzareno Trimarchi
> > Co-Founder & Chief Executive Officer
> > M. +39 347 913 2170
> > michael at amarulasolutions.com
> > __________________________________
> >
> > Amarula Solutions BV
> > Joop Geesinkweg 125, 1114 AB, Amsterdam, NL
> > T. +31 (0)85 111 9172
> > info at amarulasolutions.com
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-- 
Michael Nazzareno Trimarchi
Co-Founder & Chief Executive Officer
M. +39 347 913 2170
michael at amarulasolutions.com
__________________________________

Amarula Solutions BV
Joop Geesinkweg 125, 1114 AB, Amsterdam, NL
T. +31 (0)85 111 9172
info at amarulasolutions.com
www.amarulasolutions.com