ubifs not working with 3.1 kernel and MT29F2G08ABAEAWP NAND Flash.
Angus CLARK
angus.clark at st.com
Wed Oct 19 11:25:16 EDT 2011
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
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