Re: ubifs not working with 3.1 kernel and MT29F2G08ABAEAWP NAND Flash.

[Angus CLARK <angus.clark@st.com>]

Hi Goutam,

On 10/19/2011 03:28 PM, Kumar, Goutam wrote:
> 
> There is MT29F2G08ABAEAWP (256MB, 8-bit) NAND device on TI EVM.
> 

This particular NAND device requires 4-bit ECC.  As far as I can tell, you are
using the OMAP2 driver with 1-bit Hamming H/W ECC.  This will throw
uncorrectable ECC errors (as seen in your log) if there are 2 bit flips in any
ECC block.  The problem gets worse if there are 3 or 4 bit flips, which is still
within spec of the NAND device.

This may, or may not, be the source of your problem, but it might be worth
taking a look anyway.

The device does include a 4-bit on-die ECC engine, which can be enabled using
the 'SET_FEATURE' command.  I don't believe this is available in nand_base.c at
present, but it is not too hard to add.  You would also need to disable the
OMAP2 H/W ECC support to avoid any layout clashes in the OOB area.  Of course,
whatever changes you make to the kernel, would also have to be made to u-boot.

Cheers,

Angus