mtd: nand: allow to set only one of ECC size and ECC strength from DT

Currently, it is valid to specify both "nand-ecc-step-size" and
"nand-ecc-strength", but not allowed to set only one of them.

This requirement has a conflict with "nand-ecc-maximize"; this flag
is used when you want the driver to choose the best ECC strength.
If "nand-ecc-maximize" is set, "nand-ecc-strength" is very likely to
be unset.

It would be possible to make the if-conditional more complex by
adding the check for the NAND_ECC_MAXIMIZE flag, but I chose to drop
the check entirely.  I thought of the situation where the hardware
has a fixed ECC step size (so it can be hard-coded in the driver),
whereas the ECC strength is configurable by software.  In that case,
we may want to only set "nand-ecc-strength" (or "nand-ecc-maximize")
in DT.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 685376d8ceab2df92a58b27db468fdc1511057ee..d3545c9a792a7d6c216c262ec2671f3afd21c724 100644 (file)
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -4225,12 +4225,6 @@ static int nand_dt_init(struct nand_chip *chip)
        ecc_strength = of_get_nand_ecc_strength(dn);
        ecc_step = of_get_nand_ecc_step_size(dn);
 
-       if ((ecc_step >= 0 && !(ecc_strength >= 0)) ||
-           (!(ecc_step >= 0) && ecc_strength >= 0)) {
-               pr_err("must set both strength and step size in DT\n");
-               return -EINVAL;
-       }
-
        if (ecc_mode >= 0)
                chip->ecc.mode = ecc_mode;