diff --git a/drivers/net/phy/phy-core.c b/drivers/net/phy/phy-core.c
index 20f72f794182..a0f9ffc7d7dd 100644
--- a/drivers/net/phy/phy-core.c
+++ b/drivers/net/phy/phy-core.c
@@ -8,7 +8,7 @@
 
 const char *phy_speed_to_str(int speed)
 {
-	BUILD_BUG_ON_MSG(__ETHTOOL_LINK_MODE_MASK_NBITS != 90,
+	BUILD_BUG_ON_MSG(__ETHTOOL_LINK_MODE_MASK_NBITS != 92,
 		"Enum ethtool_link_mode_bit_indices and phylib are out of sync. "
 		"If a speed or mode has been added please update phy_speed_to_str "
 		"and the PHY settings array.\n");
@@ -160,6 +160,8 @@ static const struct phy_setting settings[] = {
 	PHY_SETTING(    100, FULL,    100baseT_Full		),
 	PHY_SETTING(    100, FULL,    100baseT1_Full		),
 	PHY_SETTING(    100, HALF,    100baseT_Half		),
+	PHY_SETTING(    100, HALF,    100baseFX_Half		),
+	PHY_SETTING(    100, FULL,    100baseFX_Full		),
 	/* 10M */
 	PHY_SETTING(     10, FULL,     10baseT_Full		),
 	PHY_SETTING(     10, HALF,     10baseT_Half		),
diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
index 40a55c129339..e95684729019 100644
--- a/include/uapi/linux/ethtool.h
+++ b/include/uapi/linux/ethtool.h
@@ -1615,6 +1615,8 @@ enum ethtool_link_mode_bit_indices {
 	ETHTOOL_LINK_MODE_400000baseLR4_ER4_FR4_Full_BIT = 87,
 	ETHTOOL_LINK_MODE_400000baseDR4_Full_BIT	 = 88,
 	ETHTOOL_LINK_MODE_400000baseCR4_Full_BIT	 = 89,
+	ETHTOOL_LINK_MODE_100baseFX_Half_BIT		 = 90,
+	ETHTOOL_LINK_MODE_100baseFX_Full_BIT		 = 91,
 	/* must be last entry */
 	__ETHTOOL_LINK_MODE_MASK_NBITS
 };
diff --git a/net/ethtool/common.c b/net/ethtool/common.c
index b76b5e984045..e911df6b3f05 100644
--- a/net/ethtool/common.c
+++ b/net/ethtool/common.c
@@ -186,6 +186,8 @@ const char link_mode_names[][ETH_GSTRING_LEN] = {
 	__DEFINE_LINK_MODE_NAME(400000, LR4_ER4_FR4, Full),
 	__DEFINE_LINK_MODE_NAME(400000, DR4, Full),
 	__DEFINE_LINK_MODE_NAME(400000, CR4, Full),
+	__DEFINE_LINK_MODE_NAME(100, FX, Half),
+	__DEFINE_LINK_MODE_NAME(100, FX, Full),
 };
 static_assert(ARRAY_SIZE(link_mode_names) == __ETHTOOL_LINK_MODE_MASK_NBITS);
 
diff --git a/net/ethtool/linkmodes.c b/net/ethtool/linkmodes.c
index 7044a2853886..29dcd675b65a 100644
--- a/net/ethtool/linkmodes.c
+++ b/net/ethtool/linkmodes.c
@@ -272,6 +272,8 @@ static const struct link_mode_info link_mode_params[] = {
 	__DEFINE_LINK_MODE_PARAMS(400000, LR4_ER4_FR4, Full),
 	__DEFINE_LINK_MODE_PARAMS(400000, DR4, Full),
 	__DEFINE_LINK_MODE_PARAMS(400000, CR4, Full),
+	__DEFINE_LINK_MODE_PARAMS(100, FX, Half),
+	__DEFINE_LINK_MODE_PARAMS(100, FX, Full),
 };
 
 static const struct nla_policy