ixgbe: limit setting speed to only one at a time for QSFP modules

QSFP+ modules do not support auto negotiation and should advertise only
one speed at a time.

This patch adds logic in ethtool to allow setting and reporting the
advertised speed at either 1Gbps or 10Gbps, but not both. Also limits
the speed set in ixgbe_sfp_link_config_subtask() to highest supported.
Previously the link was set to whatever the supported speeds were.

Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c

@@ -186,6 +186,11 @@ static int ixgbe_get_settings(struct net_device *netdev,
 			ecmd->advertising |= ADVERTISED_1000baseT_Full;
 		if (supported_link & IXGBE_LINK_SPEED_100_FULL)
 			ecmd->advertising |= ADVERTISED_100baseT_Full;
+
+		if (hw->phy.multispeed_fiber && !autoneg) {
+			if (supported_link & IXGBE_LINK_SPEED_10GB_FULL)
+				ecmd->advertising = ADVERTISED_10000baseT_Full;
+		}
 	}
 
 	if (autoneg) {
@@ -314,6 +319,14 @@ static int ixgbe_set_settings(struct net_device *netdev,
 		if (ecmd->advertising & ~ecmd->supported)
 			return -EINVAL;
 
+		/* only allow one speed at a time if no autoneg */
+		if (!ecmd->autoneg && hw->phy.multispeed_fiber) {
+			if (ecmd->advertising ==
+			    (ADVERTISED_10000baseT_Full |
+			     ADVERTISED_1000baseT_Full))
+				return -EINVAL;
+		}
+
 		old = hw->phy.autoneg_advertised;
 		advertised = 0;
 		if (ecmd->advertising & ADVERTISED_10000baseT_Full)

drivers/net/ethernet/intel/ixgbe/ixgbe_main.c

@@ -6000,8 +6000,16 @@ static void ixgbe_sfp_link_config_subtask(struct ixgbe_adapter *adapter)
 	adapter->flags &= ~IXGBE_FLAG_NEED_LINK_CONFIG;
 
 	speed = hw->phy.autoneg_advertised;
-	if ((!speed) && (hw->mac.ops.get_link_capabilities))
+	if ((!speed) && (hw->mac.ops.get_link_capabilities)) {
 		hw->mac.ops.get_link_capabilities(hw, &speed, &autoneg);
+
+		/* setup the highest link when no autoneg */
+		if (!autoneg) {
+			if (speed & IXGBE_LINK_SPEED_10GB_FULL)
+				speed = IXGBE_LINK_SPEED_10GB_FULL;
+		}
+	}
+
 	if (hw->mac.ops.setup_link)
 		hw->mac.ops.setup_link(hw, speed, true);