Cannot erase nand flash

Cannot erase nand flash

[Steve Finney]

>Date: Mon, 26 Jun 2006 10:52:43 +0200
>From: peter.hosten@rwth-aachen.de

> Unfortunately the mtd-util
>(flash_eraseall, mtd_debug) is not able to erase the NAND-Flash. I get the
>error  "./flash_eraseall: /dev/mtd3: MTD Erase failure: Input/output error"
>(see below)

>I also dumped the NAND Flash ( see below); may it be possible that it does
>not work because of the OBB data ( OOB Data: 00 00 00 00 00 00 00 00 00 00
>00 00 00 00 00 00) ?

I have seen that error with some versions of mtd-utils when the partition contains a
bad block, and your dumped OOB would be interpreted as a bad block
(no 0xFF in byte 5). But, in fact, the flash may have been successfully erased, and Linux
works reasonably well with bad blocks, so you may be able to just ignore
the "error".

sf

Re: Cannot erase nand flash

[Josh Boyer]

On 6/26/06, Steve Finney <saf76@earthlink.net> wrote:
>
> >Date: Mon, 26 Jun 2006 10:52:43 +0200
> >From: peter.hosten@rwth-aachen.de
>
> > Unfortunately the mtd-util
> >(flash_eraseall, mtd_debug) is not able to erase the NAND-Flash. I get the
> >error  "./flash_eraseall: /dev/mtd3: MTD Erase failure: Input/output error"
> >(see below)
>
> >I also dumped the NAND Flash ( see below); may it be possible that it does
> >not work because of the OBB data ( OOB Data: 00 00 00 00 00 00 00 00 00 00
> >00 00 00 00 00 00) ?
>
> I have seen that error with some versions of mtd-utils when the partition contains a
> bad block, and your dumped OOB would be interpreted as a bad block
> (no 0xFF in byte 5). But, in fact, the flash may have been successfully erased, and Linux
> works reasonably well with bad blocks, so you may be able to just ignore
> the "error".

The tool could be made to check each block to see if it's bad first
before erasing.  Then it would print a nice informative:

Block %d is bad, skipping

instead of the misleading error you get now.

josh

Re: Cannot erase nand flash

[Thomas Gleixner]

On Mon, 2006-06-26 at 10:02 -0700, Steve Finney wrote:
> >Date: Mon, 26 Jun 2006 10:52:43 +0200
> >From: peter.hosten@rwth-aachen.de
> 
> > Unfortunately the mtd-util
> >(flash_eraseall, mtd_debug) is not able to erase the NAND-Flash. I get the
> >error  "./flash_eraseall: /dev/mtd3: MTD Erase failure: Input/output error"
> >(see below)
> 
> >I also dumped the NAND Flash ( see below); may it be possible that it does
> >not work because of the OBB data ( OOB Data: 00 00 00 00 00 00 00 00 00 00
> >00 00 00 00 00 00) ?
> 
> I have seen that error with some versions of mtd-utils when the partition contains a
> bad block, and your dumped OOB would be interpreted as a bad block
> (no 0xFF in byte 5). But, in fact, the flash may have been successfully erased, and Linux
> works reasonably well with bad blocks, so you may be able to just ignore
> the "error".

Err, when oob data are all set to 0, there is something wrong.

	tglx