Nand driver acts different in two different settings

John Tobias jtobias at viaas.com
Tue May 19 16:55:10 EDT 2009


Hello all,

I have tested two scenarios for writing/reading a data on my nand
flash and it act's differently the nand driver on DM6446.

1st scenario:

I booted my board with NFS, mounted my nand flash partition manually
mount -t jffs2 /dev/mtdblock11 /mnt

Then, I put data on nand partition by copying the following
directories (/bin /lib):
cp -daR /bin /lib /mnt

I unmounted and remounted it and I didn't get any errors/warnings,
even I try many times.

2nd scenario:

I erased the said partition using flash_eraseall -j /dev/mtdblock11,
write the .jffs2 image on flash using nandwrite.
Then, I reboot my board to boot on nand. The first boot, I didn't get
any errors/warnings. But, after the 2nd reboot, I got the following
errors:

mtd->read(0x7b74 bytes from 0x2a9848c) returned ECC error
Empty flash at 0x02a9cea4 ends at 0x02a9d000
jffs2_scan_dirent_node(): Name CRC failed on node at 0x02a9d4b8: Read
0x87ca3075, calculated 0x9a7d2011
jffs2_scan_dirent_node(): Name CRC failed on node at 0x02a9e198: Read
0x1c93832c, calculated 0x1947e8af
jffs2_scan_dirent_node(): Name CRC failed on node at 0x02a9e660: Read
0xb08c7dea, calculated 0x7855f7e2
jffs2_scan_dirent_node(): Name CRC failed on node at 0x02a9eb2c: Read
0x06400c2b, calculated 0x06400c29
jffs2_scan_dirent_node(): Name CRC failed on node at 0x02a9faec: Read
0xa532c097, calculated 0x6e6e1332


Why it acts so differently the two scenarios, since I'm using same driver?.

Does booting on nand, the driver should behave differently?.
Am I missing something or is there any special cases that I need to do on nand?

Any help would be appreciated.

Thanks,

John



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