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

["Marek Behún" <marek.behun@nic.cz>]

On Tue, 22 Feb 2022 21:47:57 +0100
Pali Rohár <pali@kernel.org> wrote:

> 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.

Seems that I have trouble remembering what how I have actually
implemented it :) Oh well. Sorry about this.