[Yaffs] [Yaffs-archive] bad block problem
Skumar
skumar@mistralsoftware.com
Fri, 16 Apr 2004 10:21:49 +0530
Hi,
i want to know on what condition will yaffs mark a block bad?
my assumption is when it does a page read & compares the ecc calculated &
the ecc stored in oob
and if it does not match it marks the blcok bad. is this correct
will yaffs do write verify(ie will it read back the page after write and
check for ecc)?
Regards
sharath
>
> > Sharath
> >
> > I had exactly that problem a while back till I made sure that the ecc
> connectivity between yaffs and mtd was working right. Things like one mtd
> layer being passed an integer indicating which oob style to use and
another
> being passed a pointer into an array of oob defs. Both versions link fine
of
> course. There is also some potential for confusion with the yaffs and
smart
> media locations too.
> >
> > If it is *nearly* right then reads often seem ok but the block is marked
> as bad and when the data is moved a bad block marker stops reuse of the
> block. Erasing the bad block marks is bad as this also removes the
> manufacturer bad block marks and the mtd filters this out. For dev work I
> stomp on this filter and accept any bad consequences.
> >
> > See http://62.49.201.250/balloon/ for sample linux source trees with
yaffs
> integration - new 2.4.25-vrs2-tcl1 added recently.
> >
> > Nick
> >
> > ----- Original Message -----
> > From: "Skumar" <skumar@mistralsoftware.com>
> > To: "yaffs" <yaffs@toby-churchill.org>
> > Sent: Thursday, March 25, 2004 5:54 AM
> > Subject: bad block problem
> >
> >
> > > hin
> > > i am working on s3c2410 processor using yaffs above mtd on NAND flash.
> > > i am facing problem that sometimes the yaffs is marking all the blocks
> as
> > > bad & the yaffs partition becomes unusable.
> > > i want to know if someone has faced this problem before.
> > > i want to know whether to debug yaffs or mtd?
> > >
> > > Regards
> > > sharath
> > >
> > >
> > >
> >
>
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