[Yaffs] onenand DDP device read issue on yaffs2 filesystem!!…

Hi All, i am seeing some weired issue with yaffs2 on my onenand driver.

I have written basic onenand driver to test the read/write operations
to the device.
I am using 4Gb DDP device.Before enabling the DDP all read/writes are
happening fine.
After enabling the DDP feature i am able to read the files which falls
on the chip boundary.
but after  umount 7 mounting back the mtd partition i am loosing the
files which falls on the chip boundary.


Assumptions:

1) Using yaffs2 filesystem over mtd
2) Device 'KFN4G16Q2A DEB8
3) Read/write happends only one page at a time.Means MTD calls my
driver reads/write functions when it want to read/program at page
level.
4) Not using read-while-loading etc


ex:
suppose if i start writing a file X at the location 0x0fff_f800 (last
page in chip0 ) to 0x1006_1800 ( in chip1 ).
after umount & mount if try to read a file i am not able to retrieve
back the file, it is showing as lost+found.

while crossing the boundary i am taking care below settings

1) DFS/FBA based on 'from' address whether it is chip0 or chip1 address
2) DBS
3) FPA/FSA
4) BSA/BSC

Is there anything else do i need to takecare?

--
Regards,
Murali N