[ Upstream commit
778cb8e39f6ec252be50fc3850d66f3dcbd5dd5a ]
"PAGESIZE / 512" is the number of ECC chunks.
"ECC_BYTES" is the number of bytes needed to store a single ECC code.
"2" is the space reserved by the bad block marker.
"2 + (PAGESIZE / 512) * ECC_BYTES" should of course be lower or equal
than the total number of OOB bytes, otherwise it won't fit.
Fix the equation by substituting s/>=/<=/.
Suggested-by: Ryan J. Barnett <ryan.barnett@collins.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/linux-mtd/20210610143945.3504781-1-miquel.raynal@bootlin.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
so the device should have enough free bytes available its OOB/Spare
area to accommodate ECC for entire page. In general following expression
helps in determining if given device can accommodate ECC syndrome:
- "2 + (PAGESIZE / 512) * ECC_BYTES" >= OOBSIZE"
+ "2 + (PAGESIZE / 512) * ECC_BYTES" <= OOBSIZE"
where
OOBSIZE number of bytes in OOB/spare area
PAGESIZE number of bytes in main-area of device page