[snip]
>>> Try doing some nandwrites etc to manually do stuff to the block and see
>>> if that works.
>> How would you recommend doing this? Unmounting the YAFFS2 file system and
>> reading and writing the NAND block device directly?
> Yes, do some manual operations on an unmounted yaffs partition.
>
Thanks for the help Charles
I did this with mtd-utils and writing to the mtdblock device using dd. I didn't
seem to have any issues. The blocks that YAFFS2 were saying couldn't be erased
were erased successfully (and thus not marked bad). I will test a bit more with it.
I returned the cleaned up NAND to our application developer and it worked for a
while, but eventually started showing the same errors as previous. The file
system doesn't seem to corrupt, but blocks get in this state where they
apparently can't be erased or marked bad.
The NAND device I'm using is a 4K page 128bit OOB part. As I mentioned I had to
add some code to the kernel to get things working properly at the MTD layer. Is
there a possibility that the YAFFS2 file system doesn't like parts with 4K
pages? Or does the MTD layer make this invisible to YAFFS2?
I'm trying to get an understanding of how the OOB area is used byt both YAFFS2
and MTD without stepping on each other toes. I think I have it figured out, and
I don't think that they are trying to use the same bytes in the OOB area.
The YAFFS2 code I'm using is also older. I think I might try pulling in some
more recent code from your repository in hopes that it will fix things.
I'm also trying to get our hardware guys to source 16Gbit NAND with 2K blocks
and 64bit OOB in hopes that the problem will go away.
Anything else you'd recommend looking into?
Andrew
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