ECC & Magic bitmask errors with JFFS2 file system on 6.23 kernel for powerpc

[Rupesh Kumar]

Hi Louise,

Earlier we were using kernel 2.6.20(released with LTIB for REVA board of 
MPC8313E) and we were not seeing this problem in that kernel. Since, We 
had time constraint for our project, best thing we did was ported 2.6.20 
kernel on rev 2.1 silicon of MPC8313E. This is working fine.

However, We did try to dig this problem further and found that the problem 
occurs because of the ECC alignment mismatch in read & write on NAND 
flash.
You can look into following points :- 
        1) NAND initialization :-  Page size mentioned correctly in BR/OR 
register Settings.
        2) rfs is made with correct erase size.
        3) ECC placement used in u-boot & Kernel nand driver is same.
        4) Try using different ECC alignments and see if it makes some 
difference.


Regards 
Rupesh 





Anton Vorontsov <avorontsov at ru.mvista.com> 
09/01/2009 05:17 AM
Please respond to
avorontsov at ru.mvista.com


To
Louise.Yeung at Sun.COM
cc
linuxppc-dev at lists.ozlabs.org, louise <louise at Sun.COM>, Ravinder Kumar 
<Ravinder.Kumar at Sun.COM>, Rupesh Kumar <Rupesh.Kumar at Lntemsys.com>
Subject
Re: ECC & Magic bitmask errors with JFFS2 file system on 6.23 kernel for 
powerpc






On Mon, Aug 31, 2009 at 01:39:10PM -0700, Louise.Yeung at Sun.COM wrote:
> *Hi Rupesh,
> 
> We are using a Freescale processor similar to yours with NAND flash
> supporting 2KB page size .

What kernel version and NAND driver you use? I don't think that old
BSP kernels include fsl_elbc_nand driver, which is a much improved
version of the fsl_fcm driver.

So you might want to swith to a newer kernel or back-port the
fsl_elbc_nand driver[1] and a few fixes to your kernel.

[1] 
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=history;f=drivers/mtd/nand/fsl_elbc_nand.c


-- 
Anton Vorontsov
email: cbouatmailru at gmail.com
irc://irc.freenode.net/bd2