if (state->interface != PHY_INTERFACE_MODE_NA &&
            state->interface != PHY_INTERFACE_MODE_QSGMII &&
            state->interface != PHY_INTERFACE_MODE_SGMII &&
-           state->interface != PHY_INTERFACE_MODE_2500BASEX &&
            !phy_interface_mode_is_8023z(state->interface) &&
            !phy_interface_mode_is_rgmii(state->interface)) {
                bitmap_zero(supported, __ETHTOOL_LINK_MODE_MASK_NBITS);
        /* Asymmetric pause is unsupported */
        phylink_set(mask, Pause);
 
-       /* We cannot use 1Gbps when using the 2.5G interface. */
-       if (state->interface == PHY_INTERFACE_MODE_2500BASEX) {
-               phylink_set(mask, 2500baseT_Full);
-               phylink_set(mask, 2500baseX_Full);
-       } else {
-               phylink_set(mask, 1000baseT_Full);
-               phylink_set(mask, 1000baseX_Full);
-       }
+       /* Half-duplex at speeds higher than 100Mbit is unsupported */
+       phylink_set(mask, 1000baseT_Full);
+       phylink_set(mask, 1000baseX_Full);
 
        if (!phy_interface_mode_is_8023z(state->interface)) {
                /* 10M and 100M are only supported in non-802.3z mode */