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CRC problems with current JFFS2

DISCUSSION Wojtek Kaniewski 1 participant 1 message Aug 31, 2005 Memory technology devices (MTD)

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Hello,

Couple of days ago I tried to setup JFFS2 filesystem on a NAND chip. After dealing with missing ECC (although I enabled it in the driver) and mysterious CRC errors I went to MTD website and found that the 2.4 kernel tree that I'm using is unsupported. Unfortunately I can't switch to 2.6 because I doesn't seem to support WBC's PPChameleon boards. So I have backported current JFFS2 and MTD drivers to 2.4. Unfortunately it solved only the ECC issues. I still get CRC errors. The strange thing is that they occur only when dealing with symlinks, the rest of the filesystem is copied without complaints. For example, copying 50MB /usr results in no errors, but 5MB /lib gives:

~ # cp -a /lib /mnt/flash
Node CRC 88217c9d != calculated CRC 2e2558a6 for node at 00e779c8
cp: unable to preserve ownership of `/mnt/flash/lib/ld.so.1':
Input/output errorNode CRC 9b96bd4b != calculated CRC a58fd4f1 for node at 00d047f0
cp: unable to preserve ownership of `/mnt/flash/lib/libexpat.so':
Input/output error
Node CRC ffffffff != calculated CRC f09e7845 for node at 00945184
cp: unable to preserve ownership of `/mnt/flash/lib/libcrypt.so.1':
Input/output error

The failed symlinks are never the same. Besides, they seem quite normal even though there were errors:

~ # ls -l /mnt/flash/lib/ld.so.1
lrwxrwxrwx 1 root root 11 Jan 1 01:19
/mnt/flash/lib/ld.so.1 -> ld-2.3.1.so

I'm quite stuck now, because the only reasonable answers for CRC problems I've found in list archive and Google were flash corruption and outdated JFFS2 drivers. Unfortunately the NAND chips were soldered couple of days ago and the JFFS2 were taken from CVS HEAD this week.

The system is a modified 2.4.20 running on IBM PowerPC 405EP with backported MTD/JFFS2 drivers. NAND chip is ST NAND512Wxx. If some more information is needed I'll be glad to provide it.

Regards,
Wojtek