Hi Linus,
On 01/21/2023 03:43 PM, Linus Walleij wrote:
For BRCMNAND with 1-bit BCH ECC (BCH-1) such as used on the D-Link DIR-885L and DIR-890L routers, we need to explicitly select the ECC like this in the device tree:
nand-ecc-algo = "bch"; nand-ecc-strength = <1>; nand-ecc-step-size = <512>;
This is handled by the Linux kernel but U-Boot core does not respect this. Fix it up by parsing the algorithm and preserve the behaviour using this property to select software BCH as far as possible.
For 1 bit HW ECC, the BRCMNAND driver only uses HAMMING ECC. The brcmnand_setup_dev function should take care of it with just these two properties in the device tress without any code changes: nand-ecc-strength = <1>; nand-ecc-step-size = <512>; unless these D-Link device has always been using software BCH-1 and wants to continue to use software BCH-1.
BTW, I didn't see this change from master branch of linux nand base driver. The "nand-ecc-algo" is only used by the ecc engine code(ecc.c) but this code is not in the u-boot obviously. Were you porting this from a different version of linux nand driver?
Signed-off-by: Linus Walleij linus.walleij@linaro.org
drivers/mtd/nand/raw/nand_base.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c index 9eba360d55f3..872b58ec5f23 100644 --- a/drivers/mtd/nand/raw/nand_base.c +++ b/drivers/mtd/nand/raw/nand_base.c @@ -4487,6 +4487,7 @@ EXPORT_SYMBOL(nand_detect); static int nand_dt_init(struct mtd_info *mtd, struct nand_chip *chip, ofnode node) { int ret, ecc_mode = -1, ecc_strength, ecc_step;
int ecc_algo = NAND_ECC_UNKNOWN; const char *str;
ret = ofnode_read_s32_default(node, "nand-bus-width", -1);
@@ -4512,10 +4513,13 @@ static int nand_dt_init(struct mtd_info *mtd, struct nand_chip *chip, ofnode nod ecc_mode = NAND_ECC_SOFT_BCH; }
- if (ecc_mode == NAND_ECC_SOFT) {
str = ofnode_read_string(node, "nand-ecc-algo");if (str && !strcmp(str, "bch"))
str = ofnode_read_string(node, "nand-ecc-algo");
if (str && !strcmp(str, "bch")) {
ecc_algo = NAND_ECC_BCH;if (ecc_mode == NAND_ECC_SOFT) ecc_mode = NAND_ECC_SOFT_BCH;} else if (!strcmp(str, "hamming")) {
ecc_algo = NAND_ECC_HAMMING;}
ecc_strength = ofnode_read_s32_default(node,
@@ -4529,6 +4533,9 @@ static int nand_dt_init(struct mtd_info *mtd, struct nand_chip *chip, ofnode nod return -EINVAL; }
- if (ecc_algo >= 0)
chip->ecc.algo = ecc_algo;- if (ecc_mode >= 0) chip->ecc.mode = ecc_mode;