Re: [RFC PATCH net-next] net: mvpp2: deny disabling autoneg for 802.3z modes

[Marek Behun <marek.behun@nic.cz>]

On Mon, 12 Jul 2021 16:47:21 +0100
"Russell King (Oracle)" <rmk+kernel@armlinux.org.uk> wrote:

> The documentation for Armada 8040 says:
> 
>   Bit 2 Field InBandAnEn In-band Auto-Negotiation enable. ...
>   When <PortType> = 1 (1000BASE-X) this field must be set to 1.
> 
> We presently ignore whether userspace requests autonegotiation or not
> through the ethtool ksettings interface. However, we have some network
> interfaces that wish to do this. To offer a consistent API across
> network interfaces, deny the ability to disable autonegotiation on
> mvneta hardware when in 1000BASE-X and 2500BASE-X.
> 
> This means the only way to switch between 2500BASE-X and 1000BASE-X
> on SFPs that support this will be:
> 
>  # ethtool -s ethX advertise 0x20000006000 # 1000BASE-X Pause AsymPause
>  # ethtool -s ethX advertise 0xe000        # 2500BASE-X Pause AsymPause
> 
> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
> ---
> net-next is currently closed, but I'd like to collect acks for this
> patch. Thanks.
> 
>  drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> index 3229bafa2a2c..878fb17dea41 100644
> --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> @@ -6269,6 +6269,15 @@ static void mvpp2_phylink_validate(struct phylink_config *config,
>  		if (!mvpp2_port_supports_rgmii(port))
>  			goto empty_set;
>  		break;
> +	case PHY_INTERFACE_MODE_1000BASEX:
> +	case PHY_INTERFACE_MODE_2500BASEX:
> +		/* When in 802.3z mode, we must have AN enabled:
> +		 * Bit 2 Field InBandAnEn In-band Auto-Negotiation enable. ...
> +		 * When <PortType> = 1 (1000BASE-X) this field must be set to 1.
> +		 */
> +		if (!phylink_test(state->advertising, Autoneg))
> +			goto empty_set;
> +		break;
>  	default:
>  		break;
>  	}

Acked-by: Marek Behún <kabel@kernel.org>