diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 1ae7868d2137..e2169ca00979 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -71,6 +71,7 @@ struct phylink {
 	struct mutex state_mutex;
 	struct phylink_link_state phy_state;
 	struct work_struct resolve;
+	unsigned int pcs_neg_mode;
 
 	bool mac_link_dropped;
 	bool using_mac_select_pcs;
@@ -992,23 +993,23 @@ static void phylink_resolve_an_pause(struct phylink_link_state *state)
 	}
 }
 
-static int phylink_pcs_config(struct phylink_pcs *pcs, unsigned int mode,
+static int phylink_pcs_config(struct phylink_pcs *pcs, unsigned int neg_mode,
 			      const struct phylink_link_state *state,
 			      bool permit_pause_to_mac)
 {
 	if (!pcs)
 		return 0;
 
-	return pcs->ops->pcs_config(pcs, mode, state->interface,
+	return pcs->ops->pcs_config(pcs, neg_mode, state->interface,
 				    state->advertising, permit_pause_to_mac);
 }
 
-static void phylink_pcs_link_up(struct phylink_pcs *pcs, unsigned int mode,
+static void phylink_pcs_link_up(struct phylink_pcs *pcs, unsigned int neg_mode,
 				phy_interface_t interface, int speed,
 				int duplex)
 {
 	if (pcs && pcs->ops->pcs_link_up)
-		pcs->ops->pcs_link_up(pcs, mode, interface, speed, duplex);
+		pcs->ops->pcs_link_up(pcs, neg_mode, interface, speed, duplex);
 }
 
 static void phylink_pcs_poll_stop(struct phylink *pl)
@@ -1058,10 +1059,15 @@ static void phylink_major_config(struct phylink *pl, bool restart,
 	struct phylink_pcs *pcs = NULL;
 	bool pcs_changed = false;
 	unsigned int rate_kbd;
+	unsigned int neg_mode;
 	int err;
 
 	phylink_dbg(pl, "major config %s\n", phy_modes(state->interface));
 
+	pl->pcs_neg_mode = phylink_pcs_neg_mode(pl->cur_link_an_mode,
+						state->interface,
+						state->advertising);
+
 	if (pl->using_mac_select_pcs) {
 		pcs = pl->mac_ops->mac_select_pcs(pl->config, state->interface);
 		if (IS_ERR(pcs)) {
@@ -1094,9 +1100,12 @@ static void phylink_major_config(struct phylink *pl, bool restart,
 
 	phylink_mac_config(pl, state);
 
-	err = phylink_pcs_config(pl->pcs, pl->cur_link_an_mode, state,
-				 !!(pl->link_config.pause &
-				    MLO_PAUSE_AN));
+	neg_mode = pl->cur_link_an_mode;
+	if (pl->pcs && pl->pcs->neg_mode)
+		neg_mode = pl->pcs_neg_mode;
+
+	err = phylink_pcs_config(pl->pcs, neg_mode, state,
+				 !!(pl->link_config.pause & MLO_PAUSE_AN));
 	if (err < 0)
 		phylink_err(pl, "pcs_config failed: %pe\n",
 			    ERR_PTR(err));
@@ -1131,6 +1140,7 @@ static void phylink_major_config(struct phylink *pl, bool restart,
  */
 static int phylink_change_inband_advert(struct phylink *pl)
 {
+	unsigned int neg_mode;
 	int ret;
 
 	if (test_bit(PHYLINK_DISABLE_STOPPED, &pl->phylink_disable_state))
@@ -1149,12 +1159,20 @@ static int phylink_change_inband_advert(struct phylink *pl)
 		    __ETHTOOL_LINK_MODE_MASK_NBITS, pl->link_config.advertising,
 		    pl->link_config.pause);
 
+	/* Recompute the PCS neg mode */
+	pl->pcs_neg_mode = phylink_pcs_neg_mode(pl->cur_link_an_mode,
+					pl->link_config.interface,
+					pl->link_config.advertising);
+
+	neg_mode = pl->cur_link_an_mode;
+	if (pl->pcs->neg_mode)
+		neg_mode = pl->pcs_neg_mode;
+
 	/* Modern PCS-based method; update the advert at the PCS, and
 	 * restart negotiation if the pcs_config() helper indicates that
 	 * the programmed advertisement has changed.
 	 */
-	ret = phylink_pcs_config(pl->pcs, pl->cur_link_an_mode,
-				 &pl->link_config,
+	ret = phylink_pcs_config(pl->pcs, neg_mode, &pl->link_config,
 				 !!(pl->link_config.pause & MLO_PAUSE_AN));
 	if (ret < 0)
 		return ret;
@@ -1257,6 +1275,7 @@ static void phylink_link_up(struct phylink *pl,
 			    struct phylink_link_state link_state)
 {
 	struct net_device *ndev = pl->netdev;
+	unsigned int neg_mode;
 	int speed, duplex;
 	bool rx_pause;
 
@@ -1287,8 +1306,12 @@ static void phylink_link_up(struct phylink *pl,
 
 	pl->cur_interface = link_state.interface;
 
-	phylink_pcs_link_up(pl->pcs, pl->cur_link_an_mode, pl->cur_interface,
-			    speed, duplex);
+	neg_mode = pl->cur_link_an_mode;
+	if (pl->pcs && pl->pcs->neg_mode)
+		neg_mode = pl->pcs_neg_mode;
+
+	phylink_pcs_link_up(pl->pcs, neg_mode, pl->cur_interface, speed,
+			    duplex);
 
 	pl->mac_ops->mac_link_up(pl->config, pl->phydev, pl->cur_link_an_mode,
 				 pl->cur_interface, speed, duplex,
diff --git a/include/linux/phylink.h b/include/linux/phylink.h
index 0cf07d7d11b8..2b322d7fa51a 100644
--- a/include/linux/phylink.h
+++ b/include/linux/phylink.h
@@ -21,6 +21,24 @@ enum {
 	MLO_AN_FIXED,	/* Fixed-link mode */
 	MLO_AN_INBAND,	/* In-band protocol */
 
+	/* PCS "negotiation" mode.
+	 *  PHYLINK_PCS_NEG_NONE - protocol has no inband capability
+	 *  PHYLINK_PCS_NEG_OUTBAND - some out of band or fixed link setting
+	 *  PHYLINK_PCS_NEG_INBAND_DISABLED - inband mode disabled, e.g.
+	 *				      1000base-X with autoneg off
+	 *  PHYLINK_PCS_NEG_INBAND_ENABLED - inband mode enabled
+	 * Additionally, this can be tested using bitmasks:
+	 *  PHYLINK_PCS_NEG_INBAND - inband mode selected
+	 *  PHYLINK_PCS_NEG_ENABLED - negotiation mode enabled
+	 */
+	PHYLINK_PCS_NEG_NONE = 0,
+	PHYLINK_PCS_NEG_ENABLED = BIT(4),
+	PHYLINK_PCS_NEG_OUTBAND = BIT(5),
+	PHYLINK_PCS_NEG_INBAND = BIT(6),
+	PHYLINK_PCS_NEG_INBAND_DISABLED = PHYLINK_PCS_NEG_INBAND,
+	PHYLINK_PCS_NEG_INBAND_ENABLED = PHYLINK_PCS_NEG_INBAND |
+					 PHYLINK_PCS_NEG_ENABLED,
+
 	/* MAC_SYM_PAUSE and MAC_ASYM_PAUSE are used when configuring our
 	 * autonegotiation advertisement. They correspond to the PAUSE and
 	 * ASM_DIR bits defined by 802.3, respectively.
@@ -79,6 +97,70 @@ static inline bool phylink_autoneg_inband(unsigned int mode)
 	return mode == MLO_AN_INBAND;
 }
 
+/**
+ * phylink_pcs_neg_mode() - helper to determine PCS inband mode
+ * @mode: one of %MLO_AN_FIXED, %MLO_AN_PHY, %MLO_AN_INBAND.
+ * @interface: interface mode to be used
+ * @advertising: adertisement ethtool link mode mask
+ *
+ * Determines the negotiation mode to be used by the PCS, and returns
+ * one of:
+ * %PHYLINK_PCS_NEG_NONE: interface mode does not support inband
+ * %PHYLINK_PCS_NEG_OUTBAND: an out of band mode (e.g. reading the PHY)
+ *   will be used.
+ * %PHYLINK_PCS_NEG_INBAND_DISABLED: inband mode selected but autoneg disabled
+ * %PHYLINK_PCS_NEG_INBAND_ENABLED: inband mode selected and autoneg enabled
+ *
+ * Note: this is for cases where the PCS itself is involved in negotiation
+ * (e.g. Clause 37, SGMII and similar) not Clause 73.
+ */
+static inline unsigned int phylink_pcs_neg_mode(unsigned int mode,
+						phy_interface_t interface,
+						const unsigned long *advertising)
+{
+	unsigned int neg_mode;
+
+	switch (interface) {
+	case PHY_INTERFACE_MODE_SGMII:
+	case PHY_INTERFACE_MODE_QSGMII:
+	case PHY_INTERFACE_MODE_QUSGMII:
+	case PHY_INTERFACE_MODE_USXGMII:
+		/* These protocols are designed for use with a PHY which
+		 * communicates its negotiation result back to the MAC via
+		 * inband communication. Note: there exist PHYs that run
+		 * with SGMII but do not send the inband data.
+		 */
+		if (!phylink_autoneg_inband(mode))
+			neg_mode = PHYLINK_PCS_NEG_OUTBAND;
+		else
+			neg_mode = PHYLINK_PCS_NEG_INBAND_ENABLED;
+		break;
+
+	case PHY_INTERFACE_MODE_1000BASEX:
+	case PHY_INTERFACE_MODE_2500BASEX:
+		/* 1000base-X is designed for use media-side for Fibre
+		 * connections, and thus the Autoneg bit needs to be
+		 * taken into account. We also do this for 2500base-X
+		 * as well, but drivers may not support this, so may
+		 * need to override this.
+		 */
+		if (!phylink_autoneg_inband(mode))
+			neg_mode = PHYLINK_PCS_NEG_OUTBAND;
+		else if (linkmode_test_bit(ETHTOOL_LINK_MODE_Autoneg_BIT,
+					   advertising))
+			neg_mode = PHYLINK_PCS_NEG_INBAND_ENABLED;
+		else
+			neg_mode = PHYLINK_PCS_NEG_INBAND_DISABLED;
+		break;
+
+	default:
+		neg_mode = PHYLINK_PCS_NEG_NONE;
+		break;
+	}
+
+	return neg_mode;
+}
+
 /**
  * struct phylink_link_state - link state structure
  * @advertising: ethtool bitmask containing advertised link modes
@@ -436,6 +518,7 @@ struct phylink_pcs_ops;
 /**
  * struct phylink_pcs - PHYLINK PCS instance
  * @ops: a pointer to the &struct phylink_pcs_ops structure
+ * @neg_mode: provide PCS neg mode via "mode" argument
  * @poll: poll the PCS for link changes
  *
  * This structure is designed to be embedded within the PCS private data,
@@ -443,6 +526,7 @@ struct phylink_pcs_ops;
  */
 struct phylink_pcs {
 	const struct phylink_pcs_ops *ops;
+	bool neg_mode;
 	bool poll;
 };
 
@@ -460,12 +544,12 @@ struct phylink_pcs_ops {
 			    const struct phylink_link_state *state);
 	void (*pcs_get_state)(struct phylink_pcs *pcs,
 			      struct phylink_link_state *state);
-	int (*pcs_config)(struct phylink_pcs *pcs, unsigned int mode,
+	int (*pcs_config)(struct phylink_pcs *pcs, unsigned int neg_mode,
 			  phy_interface_t interface,
 			  const unsigned long *advertising,
 			  bool permit_pause_to_mac);
 	void (*pcs_an_restart)(struct phylink_pcs *pcs);
-	void (*pcs_link_up)(struct phylink_pcs *pcs, unsigned int mode,
+	void (*pcs_link_up)(struct phylink_pcs *pcs, unsigned int neg_mode,
 			    phy_interface_t interface, int speed, int duplex);
 };
 
@@ -508,7 +592,7 @@ void pcs_get_state(struct phylink_pcs *pcs,
 /**
  * pcs_config() - Configure the PCS mode and advertisement
  * @pcs: a pointer to a &struct phylink_pcs.
- * @mode: one of %MLO_AN_FIXED, %MLO_AN_PHY, %MLO_AN_INBAND.
+ * @neg_mode: link negotiation mode (see below)
  * @interface: interface mode to be used
  * @advertising: adertisement ethtool link mode mask
  * @permit_pause_to_mac: permit forwarding pause resolution to MAC
@@ -526,8 +610,12 @@ void pcs_get_state(struct phylink_pcs *pcs,
  * For 1000BASE-X, the advertisement should be programmed into the PCS.
  *
  * For most 10GBASE-R, there is no advertisement.
+ *
+ * The %neg_mode argument should be tested via the phylink_mode_*() family of
+ * functions, or for PCS that set pcs->neg_mode true, should be tested
+ * against the %PHYLINK_PCS_NEG_* definitions.
  */
-int pcs_config(struct phylink_pcs *pcs, unsigned int mode,
+int pcs_config(struct phylink_pcs *pcs, unsigned int neg_mode,
 	       phy_interface_t interface, const unsigned long *advertising,
 	       bool permit_pause_to_mac);
 
@@ -543,7 +631,7 @@ void pcs_an_restart(struct phylink_pcs *pcs);
 /**
  * pcs_link_up() - program the PCS for the resolved link configuration
  * @pcs: a pointer to a &struct phylink_pcs.
- * @mode: link autonegotiation mode
+ * @neg_mode: link negotiation mode (see below)
  * @interface: link &typedef phy_interface_t mode
  * @speed: link speed
  * @duplex: link duplex
@@ -552,8 +640,12 @@ void pcs_an_restart(struct phylink_pcs *pcs);
  * the resolved link parameters. For example, a PCS operating in SGMII
  * mode without in-band AN needs to be manually configured for the link
  * and duplex setting. Otherwise, this should be a no-op.
+ *
+ * The %mode argument should be tested via the phylink_mode_*() family of
+ * functions, or for PCS that set pcs->neg_mode true, should be tested
+ * against the %PHYLINK_PCS_NEG_* definitions.
  */
-void pcs_link_up(struct phylink_pcs *pcs, unsigned int mode,
+void pcs_link_up(struct phylink_pcs *pcs, unsigned int neg_mode,
 		 phy_interface_t interface, int speed, int duplex);
 #endif
 
