Issue with 'ubi part' ubi_io_read: error -74 (ECC error)

[Richard Weinberger]

On Sun, May 17, 2020 at 1:28 PM Jupiter <jupiter.hce at gmail.com> wrote:
>
> Sorry for a bit recalcitrant with the issue of calling 'ubi part"
> error -74 -EBADMSG, is it MTD issue or u-boot issue?
>
> I used Linux kernel 4.19 to flash UBIFS volume images ubi.img to
> imx6ull NAND using following command in Linux:
>
> flash_erase /dev/mtd2 0 0
> ubiformat /dev/mtd2 -f ubi.img
>
> The flashing image process went well, not errors, but in NAND booting
> (u-boot version 2018), running "ubi part" stuck following errors:
>
> ubi0 error: ubi_io_read: error -74 (ECC error) while reading 64 bytes from PEB 2
> 35:0, read 64 bytes
> ubi0 error: ubi_io_read: error -74 (ECC error) while reading 2048 bytes from PEB
>  235:2048, read 2048 bytes
>
> The document says "The -74 error code is -EBADMSG and means an ECC
> error. In other words, UBI tried to read some data from the flash, but
> the flash driver found that there is an uncorrectable ECC error, and
> returned -EBADMSG."
>
> My question for ubiformat, how does it write ECC to UBIFS volume
> partition when it flashed UBIFS image to NAND?

Neither UBI nor UBIFS care about ECC. The MTD stack does.
If you write something in Linux you cannot read back in u-boot a common
problem is that u-boot and Linux use different MTD settings (layout,
ECC, etc...).

-- 
Thanks,
//richard