[EXT] [PATCH] mtd: mxs_nand: default to legacy bch and rename to modern bch option

Sean Nyekjaer sean at geanix.com
Mon May 10 22:08:50 PDT 2021


On 11/05/2021 04.49, han.xu wrote:
> On 21/05/10 12:00PM, Sean Nyekjaer wrote:
>> Caution: EXT Email
>>
>> Linux kernel defaults to use legacy bch setting, this was creating a
>> mismatch between U-boot and Linux default settings.
> Kernel uses the NAND chip specified minimum ecc strength and steps by default
> not the legacy bch setting, unless users enable it in DT file.
> 

Hi,

Adding, mtd-list and Miquel

With u-boot dtb:
&gpmi {
	pinctrl-names = "default";
	pinctrl-0 = <&pinctrl_gpmi_nand1>;
	compatible = "fsl,imx7d-gpmi-nand";
	nand-on-flash-bbt;
	status = "okay";
};

With linux dtb (mainline 5.10):
&gpmi {
	pinctrl-names = "default";
	pinctrl-0 = <&pinctrl_gpmi_nand1>;
	nand-on-flash-bbt;
	status = "okay";
};

U-boot prior to commit 51cdf83eea selected 18 bit ECC, after that commit it selects 8 bits.
With legacy option it selects 18.
Linux is selecting 18 bits ;) So now we have a mismatch.

I have been searching for the legacy option in the mainline kernel can't find it ;)
Please show me where it is (is it in the NXP fork?)

/Sean



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