For large page chips, nand_bbt is looking into OOB area, and checking for "0xff 0xff" pattern at OOB offset 0. That is, two bytes should be reserved for bbt means. But ELBC driver is specifying ecclayout so that oobfree area starts at offset 1, so only one byte left for the bbt purposes. This causes problems with any OOB users, namely JFFS2: after first mount JFFS2 will fill all OOBs with "erased marker", so OOBs will contain: OOB Data: ff 19 85 20 03 00 ff ff ff 00 00 08 ff ff ff ff OOB Data: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff OOB Data: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff OOB Data: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff And on the next boot, NAND core will rescan for bad blocks, then will see "0xff 0x19" pattern, and will mark all blocks as bad ones. To fix the issue we should implement our own bad block pattern: just one byte at OOB start. Though, this will work only for x8 chips. For x16 chips two bytes must be checked. Since ELBC driver does not support x16 NANDs (yet), we're safe for now. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: Scott Wood <scottwood@freescale.com>master
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