From 666b65683dad9aa90efaa4aad24ef3710101e3aa Mon Sep 17 00:00:00 2001 From: Brian Norris Date: Mon, 25 Apr 2016 22:53:55 -0700 Subject: [PATCH] mtd: brcmnand: respect ECC algorithm set by NAND subsystem MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This is more obvious than guessing based on ECC strength. It allows using NAND on devices with BCH-1 (e.g. D-Link DIR-885L). This maintains DT backward compatibility by defaulting to Hamming if a 1-bit ECC algorithm is specified without a corresponding algorithm selection. i.e., to use BCH-1, you must specify: nand-ecc-strength = <1>; nand-ecc-step-size = <512>; nand-ecc-algo = "bch"; Also adds a check to ensure we haven't allowed someone to get by with SW ECC. If we want to support SW ECC, we need to refactor some other pieces of this driver. Signed-off-by: Brian Norris Tested-by: Rafał Miłecki Signed-off-by: Boris Brezillon --- drivers/mtd/nand/brcmnand/brcmnand.c | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) diff --git a/drivers/mtd/nand/brcmnand/brcmnand.c b/drivers/mtd/nand/brcmnand/brcmnand.c index c3331ffcaffd..b76ad7c0144f 100644 --- a/drivers/mtd/nand/brcmnand/brcmnand.c +++ b/drivers/mtd/nand/brcmnand/brcmnand.c @@ -1925,9 +1925,31 @@ static int brcmnand_setup_dev(struct brcmnand_host *host) cfg->col_adr_bytes = 2; cfg->blk_adr_bytes = get_blk_adr_bytes(mtd->size, mtd->writesize); + if (chip->ecc.mode != NAND_ECC_HW) { + dev_err(ctrl->dev, "only HW ECC supported; selected: %d\n", + chip->ecc.mode); + return -EINVAL; + } + + if (chip->ecc.algo == NAND_ECC_UNKNOWN) { + if (chip->ecc.strength == 1 && chip->ecc.size == 512) + /* Default to Hamming for 1-bit ECC, if unspecified */ + chip->ecc.algo = NAND_ECC_HAMMING; + else + /* Otherwise, BCH */ + chip->ecc.algo = NAND_ECC_BCH; + } + + if (chip->ecc.algo == NAND_ECC_HAMMING && (chip->ecc.strength != 1 || + chip->ecc.size != 512)) { + dev_err(ctrl->dev, "invalid Hamming params: %d bits per %d bytes\n", + chip->ecc.strength, chip->ecc.size); + return -EINVAL; + } + switch (chip->ecc.size) { case 512: - if (chip->ecc.strength == 1) /* Hamming */ + if (chip->ecc.algo == NAND_ECC_HAMMING) cfg->ecc_level = 15; else cfg->ecc_level = chip->ecc.strength; -- 2.20.1