igc: Fix ambiguity in the ethtool advertising

The 'ethtool_convert_link_mode_to_legacy_u32' method does not allow us to
advertise 2500M speed support and TP (twisted pair) properly. Convert to
'ethtool_link_ksettings_test_link_mode' to advertise supported speed and
eliminate ambiguity.

Fixes: 8c5ad0da ("igc: Add ethtool support")
Suggested-by: Dima Ruinskiy <dima.ruinskiy@intel.com>
Suggested-by: Vitaly Lifshits <vitaly.lifshits@intel.com>
Signed-off-by: Sasha Neftin <sasha.neftin@intel.com>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://lore.kernel.org/r/20231019203641.3661960-1-jacob.e.keller@intel.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/intel/igc/igc_ethtool.c

@@ -1817,7 +1817,7 @@ igc_ethtool_set_link_ksettings(struct net_device *netdev,
 	struct igc_adapter *adapter = netdev_priv(netdev);
 	struct net_device *dev = adapter->netdev;
 	struct igc_hw *hw = &adapter->hw;
-	u32 advertising;
+	u16 advertised = 0;
 
 	/* When adapter in resetting mode, autoneg/speed/duplex
 	 * cannot be changed
@@ -1842,18 +1842,33 @@ igc_ethtool_set_link_ksettings(struct net_device *netdev,
 	while (test_and_set_bit(__IGC_RESETTING, &adapter->state))
 		usleep_range(1000, 2000);
 
-	ethtool_convert_link_mode_to_legacy_u32(&advertising,
-						cmd->link_modes.advertising);
-	/* Converting to legacy u32 drops ETHTOOL_LINK_MODE_2500baseT_Full_BIT.
-	 * We have to check this and convert it to ADVERTISE_2500_FULL
-	 * (aka ETHTOOL_LINK_MODE_2500baseX_Full_BIT) explicitly.
-	 */
-	if (ethtool_link_ksettings_test_link_mode(cmd, advertising, 2500baseT_Full))
-		advertising |= ADVERTISE_2500_FULL;
+	if (ethtool_link_ksettings_test_link_mode(cmd, advertising,
+						  2500baseT_Full))
+		advertised |= ADVERTISE_2500_FULL;
+
+	if (ethtool_link_ksettings_test_link_mode(cmd, advertising,
+						  1000baseT_Full))
+		advertised |= ADVERTISE_1000_FULL;
+
+	if (ethtool_link_ksettings_test_link_mode(cmd, advertising,
+						  100baseT_Full))
+		advertised |= ADVERTISE_100_FULL;
+
+	if (ethtool_link_ksettings_test_link_mode(cmd, advertising,
+						  100baseT_Half))
+		advertised |= ADVERTISE_100_HALF;
+
+	if (ethtool_link_ksettings_test_link_mode(cmd, advertising,
+						  10baseT_Full))
+		advertised |= ADVERTISE_10_FULL;
+
+	if (ethtool_link_ksettings_test_link_mode(cmd, advertising,
+						  10baseT_Half))
+		advertised |= ADVERTISE_10_HALF;
 
 	if (cmd->base.autoneg == AUTONEG_ENABLE) {
 		hw->mac.autoneg = 1;
-		hw->phy.autoneg_advertised = advertising;
+		hw->phy.autoneg_advertised = advertised;
 		if (adapter->fc_autoneg)
 			hw->fc.requested_mode = igc_fc_default;
 	} else {