From 3998a4611e8be2e9b5833e7aae29619ea0305437 Mon Sep 17 00:00:00 2001 From: Samuel Holland Date: Sat, 4 Feb 2023 08:35:18 -0600 Subject: [PATCH] mtd: rawnand: sunxi: Update OOB layout to match hardware When using the hardware ECC engine, the OOB data is made available in the NFC_REG_USER_DATA registers, as one 32-bit word per ECC step. Any additional bytes are only accessible through raw reads and software descrambling. For efficiency, and to match the vendor driver, ignore these extra bytes when using hardware ECC. Note that until commit 34569d869532 ("mtd: rawnand: sunxi: Fix the size of the last OOB region"), this extra free area was reported with length zero, so this is not a functional change for any stable kernel user. Signed-off-by: Samuel Holland Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20230204143520.9682-2-samuel@sholland.org --- drivers/mtd/nand/raw/sunxi_nand.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/mtd/nand/raw/sunxi_nand.c b/drivers/mtd/nand/raw/sunxi_nand.c index e673ac4..3c32d31 100644 --- a/drivers/mtd/nand/raw/sunxi_nand.c +++ b/drivers/mtd/nand/raw/sunxi_nand.c @@ -1604,6 +1604,13 @@ static int sunxi_nand_ooblayout_free(struct mtd_info *mtd, int section, return 0; } + /* + * The controller does not provide access to OOB bytes + * past the end of the ECC data. + */ + if (section == ecc->steps && ecc->engine_type == NAND_ECC_ENGINE_TYPE_ON_HOST) + return -ERANGE; + oobregion->offset = section * (ecc->bytes + 4); if (section < ecc->steps) -- 2.7.4