mtd oob test is failing consistently at same places in NAND flash

[Ivan Djelic]

On Tue, May 08, 2012 at 04:09:46PM +0100, Philip, Avinash wrote:
> On Tue, May 08, 2012 at 18:53:54, Ivan Djelic wrote:
> > On Tue, May 08, 2012 at 01:33:06PM +0100, Philip, Avinash wrote:
> > > Hi,
> > > 
> > > We are having an 8-bit NAND part (MT29F2G08ABAEAWP from Micron) 
> > > connected to GPMC Module (General purpose memory controller) from TI.
> > 
> > Hi,
> > How is ecc performed ?
> > Using NAND internal ecc ? or with GPMC 1-bit Hamming ? 4-bit/8-bit BCH ?
> > Which version of omap2 driver are you using ?
> > Is OOB also ECC-protected ?
> 
> Hardware ECC is performing.
> 4-bit BCH ECC scheme is used.
> I am using omap2 driver in Linux 3.2.0 Kernel. Don't know omap2 driver version.

You are probably using a patched kernel, since 3.2.0 does not have GPMC BCH support ?!
What is your ecc layout ? Does it expose oobfree regions ?

> No, OOB is not ECC protected.

Well, in that case, isn't it normal that mtd_oobtest should fail if there happens to be
a single bitflip in the available OOB area ? (of size mtd->ecclayout->oobavail for each page)

BR,
--
Ivan