[PATCH RFC net-next 05/12] net: mtk_eth_soc: correct 802.3z duplex setting

[Russell King]

Phylink does not guarantee that state->duplex will be set correctly in
the mac_config() call, so it's a bug that the driver makes use of it.

Move the 802.3z PCS duplex configuration to mac_link_up().

Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c | 16 +++++++++++----
 drivers/net/ethernet/mediatek/mtk_eth_soc.h |  1 +
 drivers/net/ethernet/mediatek/mtk_sgmii.c   | 22 +++++++++++++++------
 3 files changed, 29 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index e491d43f049a..6fedfa8fceb1 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -482,8 +482,18 @@ static void mtk_mac_link_up(struct phylink_config *config,
 {
 	struct mtk_mac *mac = container_of(config, struct mtk_mac,
 					   phylink_config);
-	u32 mcr = mtk_r32(mac->hw, MTK_MAC_MCR(mac->id));
+	u32 mcr;
+
+	if (phy_interface_mode_is_8023z(interface)) {
+		struct mtk_eth *eth = mac->hw;
+
+		/* Decide how GMAC and SGMIISYS be mapped */
+		int sid = (MTK_HAS_CAPS(eth->soc->caps, MTK_SHARED_SGMII)) ?
+			   0 : mac->id;
+		mtk_sgmii_link_up(eth->sgmii, sid, speed, duplex);
+	}
 
+	mcr = mtk_r32(mac->hw, MTK_MAC_MCR(mac->id));
 	mcr &= ~(MAC_MCR_SPEED_100 | MAC_MCR_SPEED_1000 |
 		 MAC_MCR_FORCE_DPX | MAC_MCR_FORCE_TX_FC |
 		 MAC_MCR_FORCE_RX_FC);
@@ -2972,9 +2982,7 @@ static int mtk_add_mac(struct mtk_eth *eth, struct device_node *np)
 
 	mac->phylink_config.dev = &eth->netdev[id]->dev;
 	mac->phylink_config.type = PHYLINK_NETDEV;
-	/* This driver makes use of state->speed/state->duplex in
-	 * mac_config
-	 */
+	/* This driver makes use of state->speed in mac_config */
 	mac->phylink_config.legacy_pre_march2020 = true;
 	mac->phylink_config.mac_capabilities = MAC_ASYM_PAUSE | MAC_SYM_PAUSE |
 		MAC_10 | MAC_100 | MAC_1000 | MAC_2500FD;
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index f31ef594008a..1912f84922c8 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -1007,6 +1007,7 @@ int mtk_sgmii_init(struct mtk_sgmii *ss, struct device_node *np,
 int mtk_sgmii_setup_mode_an(struct mtk_sgmii *ss, int id);
 int mtk_sgmii_setup_mode_force(struct mtk_sgmii *ss, int id,
 			       const struct phylink_link_state *state);
+void mtk_sgmii_link_up(struct mtk_sgmii *ss, int id, int speed, int duplex);
 void mtk_sgmii_restart_an(struct mtk_eth *eth, int mac_id);
 
 int mtk_gmac_sgmii_path_setup(struct mtk_eth *eth, int mac_id);
diff --git a/drivers/net/ethernet/mediatek/mtk_sgmii.c b/drivers/net/ethernet/mediatek/mtk_sgmii.c
index 16e66c0cb557..a5ec61e13b85 100644
--- a/drivers/net/ethernet/mediatek/mtk_sgmii.c
+++ b/drivers/net/ethernet/mediatek/mtk_sgmii.c
@@ -82,14 +82,10 @@ int mtk_sgmii_setup_mode_force(struct mtk_sgmii *ss, int id,
 	val &= ~SGMII_AN_ENABLE;
 	regmap_write(ss->regmap[id], SGMSYS_PCS_CONTROL_1, val);
 
-	/* SGMII force mode setting */
+	/* Set the speed etc but leave the duplex unchanged */
 	regmap_read(ss->regmap[id], SGMSYS_SGMII_MODE, &val);
-	val &= ~SGMII_IF_MODE_MASK;
+	val &= SGMII_DUPLEX_FULL | ~SGMII_IF_MODE_MASK;
 	val |= SGMII_SPEED_1000;
-
-	if (state->duplex == DUPLEX_FULL)
-		val |= SGMII_DUPLEX_FULL;
-
 	regmap_write(ss->regmap[id], SGMSYS_SGMII_MODE, val);
 
 	/* Release PHYA power down state */
@@ -100,6 +96,20 @@ int mtk_sgmii_setup_mode_force(struct mtk_sgmii *ss, int id,
 	return 0;
 }
 
+/* For 1000BASE-X and 2500BASE-X interface modes */
+void mtk_sgmii_link_up(struct mtk_sgmii *ss, int id, int speed, int duplex)
+{
+	unsigned int val;
+
+	/* SGMII force duplex setting */
+	regmap_read(ss->regmap[id], SGMSYS_SGMII_MODE, &val);
+	val &= ~SGMII_DUPLEX_FULL;
+	if (duplex == DUPLEX_FULL)
+		val |= SGMII_DUPLEX_FULL;
+
+	regmap_write(ss->regmap[id], SGMSYS_SGMII_MODE, val);
+}
+
 void mtk_sgmii_restart_an(struct mtk_eth *eth, int mac_id)
 {
 	struct mtk_sgmii *ss = eth->sgmii;
-- 
2.30.2