Re: [Yaffs] yaffs2 mount failure after sometime

On Tuesday 31 July 2007 07:16, Raj Kumar Yadav wrote:
> I am using ARM9 based board with 512MB large page(2K page,
> 256K Block) nand flash. The linux kernel version is 2.6.14
> with yaffs source on date July
> 12, 2007 from
> http://www.aleph1.co.uk/cgi-bin/viewcvs.cgi/yaffs2/.
<snip>

> nandmtd2_ReadChunkWithTagsToNAND chunk 60290 data 00000000
> tags c0ae9ccc packed tags obj -1 chunk -1 byte -1 seq -1
> ext.tags eccres 0 blkbad 0 chused 0 obj 0 chunk0 byte 0 del 0
> ser 0 seq 0 Allocating from 472 2
> nandmtd2_ReadChunkWithTagsToNAND chunk 60289 data 00000000
> tags c0ae9ccc packed tags obj -1 chunk -1 byte -1 seq -1
> ext.tags eccres 0 blkbad 0 chused 0 obj 0 chunk0 byte 0 del 0
> ser 0 seq 0 Allocating from 472 1
> nandmtd2_ReadChunkWithTagsToNAND chunk 60288 data 00000000
> tags c0ae9ccc packed tags obj 117900047 chunk 117698535 byte
> 117902083 seq 117905375 ext.tags eccres 3 blkbad 0 chused 1
> obj 117900047 chunk117698535 byte 117902083 del 0 ser 0 seq
> 117905375
> yaffs: Tnodes added
> yaffs: yaffs_GutsInitialise() aborted.


Some decoding...
The "ext.tags eccres 3" indicates that an underlying NAND page
read has failed with YAFFS_ECC_RESULT_UNFIXED (3). This may have
come from the MTD's NAND read returning -EBADMSG, or Yaffs's tags
ecc test. Probably the later because this error is during the
mount scan. Either way, the data read from chunk/page 60288 is
bad.

So why is it bad? If you try to mount the same device in the
same state several times, is this error reproducible?
You will have to do some arithmetic to figure out where on
NAND the page is located, you need to know the NAND partition
offset as a base. Then you might try reading the page using MTD's
nanddump utility for example. Is it possible you lost power
during a write or erase?

I'd don't know why this was a fatal error that stopped the
mount dead in it's racks, Charles?

BTW: which NAND chip are you using that has 256KB blocks?

-imcd