net: mvpp2: update mvpp2 validate() implementation

Fix up the mvpp2 validate implementation to adopt the same behaviour as
mvneta:
- only allow the link modes that the specified PHY interface mode
  supports with the exception of 1000base-X and 2500base-X.
- use the basex helper to deal with SFP modules that can be switched
  between 1000base-X vs 2500base-X.

This gives consistent behaviour between mvneta and mvpp2.

This commit depends on "net: phylink: extend clause 45 PHY validation
workaround" so is not marked for backporting to stable kernels.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Antoine Tenart <antoine.tenart@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c

@@ -4792,6 +4792,8 @@ static void mvpp2_phylink_validate(struct phylink_config *config,
 			phylink_set(mask, 10000baseER_Full);
 			phylink_set(mask, 10000baseKR_Full);
 		}
+		if (state->interface != PHY_INTERFACE_MODE_NA)
+			break;
 		/* Fall-through */
 	case PHY_INTERFACE_MODE_RGMII:
 	case PHY_INTERFACE_MODE_RGMII_ID:
@@ -4802,13 +4804,23 @@ static void mvpp2_phylink_validate(struct phylink_config *config,
 		phylink_set(mask, 10baseT_Full);
 		phylink_set(mask, 100baseT_Half);
 		phylink_set(mask, 100baseT_Full);
+		phylink_set(mask, 1000baseT_Full);
+		phylink_set(mask, 1000baseX_Full);
+		if (state->interface != PHY_INTERFACE_MODE_NA)
+			break;
 		/* Fall-through */
 	case PHY_INTERFACE_MODE_1000BASEX:
 	case PHY_INTERFACE_MODE_2500BASEX:
+		if (port->comphy ||
+		    state->interface != PHY_INTERFACE_MODE_2500BASEX) {
 			phylink_set(mask, 1000baseT_Full);
 			phylink_set(mask, 1000baseX_Full);
+		}
+		if (port->comphy ||
+		    state->interface == PHY_INTERFACE_MODE_2500BASEX) {
 			phylink_set(mask, 2500baseT_Full);
 			phylink_set(mask, 2500baseX_Full);
+		}
 		break;
 	default:
 		goto empty_set;
@@ -4817,6 +4829,8 @@ static void mvpp2_phylink_validate(struct phylink_config *config,
 	bitmap_and(supported, supported, mask, __ETHTOOL_LINK_MODE_MASK_NBITS);
 	bitmap_and(state->advertising, state->advertising, mask,
 		   __ETHTOOL_LINK_MODE_MASK_NBITS);
+
+	phylink_helper_basex_speed(state);
 	return;
 
 empty_set: