Unmarking bad blocks?

[Andriy Korud]

Hi,
after playing with mkfs.jffs2 and nandwrite a lot of blocks on my flash chip (Samsung 128Mb) become marked as bad (and I'm sure they were not bad at the beginning).
Is it possible to 'unmark' them or should this chip is unusble anymore?
flash_eraseall gives:

nand_erase: attempt to erase a bad block at page 0x00000000
nand_erase: attempt to erase a bad block at page 0x00000040
nand_erase: attempt to erase a bad block at page 0x00000080
nand_erase: attempt to erase a bad block at page 0x000000c0
...

Even I commented out bad block checking in nand_erase(), flash_eraseall comlete successfully however blocks remain marked as bad.

Any ideas?

Thanks in advance,

--

Andriy Korud