[Yaffs] Flipped bits in files on YAFFS partition, but not de…

Hello,

I am maintaining user space software on a Linux system with YAFFS1.

The hardware is now 5 years old and we observe occasionally flipped bits
in files that are stored on a YAFFS1 partition (ECC is enabled).

To my surprise, there are no CRC errors in dmesg, no eccUnfixed
entries in /proc/yaffs
or anything else that looks like the flash has a problem...

Is it possible to have flipped bits in files and
the flipping is not detected by the YAFFS layer?

Thank you for any helpful pointers,
Christian



Our embedded Linux system:
- Kernel 2.6.14.3
- YAFFS1 yaffs_fs.c,v 1.38 2005/12/15
- ARM9 Samsung S3C2410A
- 32MB NAND Samsung K9F5608U0C

/ # cat /proc/yaffs
YAFFS built:Sep 4 2006 16:33:14
$Id: yaffs_fs.c,v 1.38 2005/12/15 20:27:56 charles Exp $
$Id: yaffs_guts.c,v 1.27 2005/12/20 04:02:18 charles Exp $

Device 0 "JFFS2"
startBlock......... 0
endBlock........... 1962
chunkGroupBits..... 0
chunkGroupSize..... 1
nErasedBlocks...... 1049
nTnodesCreated..... 2300
nFreeTnodes........ 189
nObjectsCreated.... 800
nFreeObjects....... 80
nFreeChunks........ 37505
nPageWrites........ 8325
nPageReads......... 13666
nBlockErasures..... 132
nGCCopies.......... 155
garbageCollections. 132
passiveGCs......... 132
nRetriedWrites..... 0
nRetireBlocks...... 0
eccFixed........... 0
eccUnfixed......... 0
tagsEccFixed....... 0
tagsEccUnfixed..... 0
cacheHits.......... 0
nDeletedFiles...... 124
nUnlinkedFiles..... 125
nBackgroudDeletions 0
useNANDECC......... 0
isYaffs2........... 0