This is a note to let you know that I've just added the patch titled
dt-bindings: mtd: gpmc: Fix the ECC bytes vs. OOB bytes equation
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
dt-bindings-mtd-gpmc-fix-the-ecc-bytes-vs.-oob-bytes.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 9d7b89c0089d3673df5228a042b72f13946061f7
Author: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
Date: Thu Jun 10 16:39:45 2021 +0200
dt-bindings: mtd: gpmc: Fix the ECC bytes vs. OOB bytes equation
[ 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@xxxxxxxxxxx>
Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
Acked-by: Rob Herring <robh@xxxxxxxxxx>
Link: https://lore.kernel.org/linux-mtd/20210610143945.3504781-1-miquel.raynal@xxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt
index 44919d48d241..c459f169a904 100644
--- a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt
+++ b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt
@@ -122,7 +122,7 @@ on various other factors also like;
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
