Re: dangerous NAND_BBT_SCANBYTE1AND6

[Artem Bityutskiy <dedekind1@gmail.com>]

On Fri, 2011-04-22 at 10:53 +0200, Matthieu CASTET wrote:
> Artem Bityutskiy a écrit :
> > On Thu, 2011-04-21 at 19:10 +0200, Ivan Djelic wrote:
> >> On Thu, Apr 21, 2011 at 04:52:59PM +0100, Matthieu Castet wrote:
> >>> Hi,
> >>>
> >>> I believe NAND_BBT_SCANBYTE1AND6 behavior is very dangerous.
> >>> We have a ST flash where ecc where but on bit 5 and 6.
> >>> With new kernel all block are bad.
> >>>
> >>> Is this option is really needed ?
> >>> ST datasheet say [1]. We already check the first Word.
> >>> Why do we need to check the 6th Byte ?
> >> I agree with Matthieu, NAND_BBT_SCANBYTE1AND6 code also seems wrong to me.
> > 
> > This just means that we need a better way for drivers to inform the
> > generic code about how exactly blocks are marked as bad. Probably
> > drivers could describe this with a data structure, and sometimes even
> > provide a "is_block_bad()" function.
> > 
> > The options seem to be not enough.
> > 
> I think we should also unify bad block scanning.

Sure, just do this in small incremental steps, send small incremental
patches with nice description (and tested). The point is - you should
not wait when someone else fixes this for you - i do not think this
happens. Additional thing - if you are using MTD and interested in its
stability - review others patches which touch the area of your
interests :-)

-- 
Best Regards,
Artem Bityutskiy (Артём Битюцкий)