[PATCH u-boot-mvebu 5/5] arm: mvebu: a37xx: Add support for reading Security OTP values

[Pali Rohár]

On Thursday 17 February 2022 15:31:10 Marek Behún wrote:
> > +	 * But this command does not provide access to lock bit.
> > +	 */
> > +	if (word < 2) {
> > +		in[0] = row;
> > +		in[1] = word * 32;
> > +		res = mbox_do_cmd(MBOX_CMD_OTP_READ_32B, in, 2, out, 2);
> > +		if (res != -ENOSYS) {
> > +			if (!res)
> > +				*data = out[0];
> > +			return res;
> > +		}
> > +		/* Fallback for old version of CZ.NIC wtmi firmware. */
> > +	}
> 
> I am afraid this is not correct, because Marvell's firmware reads the
> efuse without Error Correction. So it is possible for Marvell's command
> to return different value than CZ.NIC's command.

This is not truth. CZ.NIC firmware for MBOX_CMD_OTP_READ command calls
efuse_read_row_no_ecc which is not doing error correction too.

So both commands return same value, without error correction.