[openwrt/openwrt] realtek: dsa: enhance pcs_get_state() for RTL93xx

[LEDE Commits]

hauke pushed a commit to openwrt/openwrt.git, branch main:
https://git.openwrt.org/9ccfca33038ac27cedca6f6bb18f18c47a7e38d0

commit 9ccfca33038ac27cedca6f6bb18f18c47a7e38d0
Author: Harshal Gohel <hg at simonwunderlich.de>
AuthorDate: Mon Jul 14 10:37:28 2025 +0200

    realtek: dsa: enhance pcs_get_state() for RTL93xx
    
    Currently the SerDes driven SFP ports give strange ethtool readings
    on RTL93xx devices. Especially duplex and speed are shown even if
    no link is up and running. That leads to confusion because the MAC
    reports arbitrary values.
    
    Enhance the readout by refactoring the pcs_get_state() function.
    Calculate speed/duplex/pause only if link is detected.
    
    Suggested-by: Markus Stockhausen <markus.stockhausen at gmx.de>
    Signed-off-by: Harshal Gohel <hg at simonwunderlich.de>
    Signed-off-by: Sharadanand Karanjkar <sk at simonwunderlich.de>
    Link: https://github.com/openwrt/openwrt/pull/19575
    Signed-off-by: Hauke Mehrtens <hauke at hauke-m.de>
---
 .../files-6.12/drivers/net/dsa/rtl83xx/dsa.c       | 53 ++++++++++------------
 1 file changed, 24 insertions(+), 29 deletions(-)

diff --git a/target/linux/realtek/files-6.12/drivers/net/dsa/rtl83xx/dsa.c b/target/linux/realtek/files-6.12/drivers/net/dsa/rtl83xx/dsa.c
index 10438298ad..a14b502cf1 100644
--- a/target/linux/realtek/files-6.12/drivers/net/dsa/rtl83xx/dsa.c
+++ b/target/linux/realtek/files-6.12/drivers/net/dsa/rtl83xx/dsa.c
@@ -621,8 +621,8 @@ static void rtldsa_83xx_pcs_get_state(struct phylink_pcs *pcs, struct phylink_li
 		state->pause |= MLO_PAUSE_TX;
 }
 
-static void rtl93xx_pcs_get_state(struct phylink_pcs *pcs,
-				  struct phylink_link_state *state)
+static void rtldsa_93xx_pcs_get_state(struct phylink_pcs *pcs,
+				      struct phylink_link_state *state)
 {
 	struct rtl838x_pcs *rtpcs = container_of(pcs, struct rtl838x_pcs, pcs);
 	struct rtl838x_switch_priv *priv = rtpcs->priv;
@@ -631,21 +631,25 @@ static void rtl93xx_pcs_get_state(struct phylink_pcs *pcs,
 	u64 link;
 	u64 media;
 
-	if (port < 0 || port > priv->cpu_port) {
-		state->link = false;
+	state->link = 0;
+	state->speed = SPEED_UNKNOWN;
+	state->duplex = DUPLEX_UNKNOWN;
+	state->pause &= ~(MLO_PAUSE_RX | MLO_PAUSE_TX);
+
+	if (port < 0 || port > priv->cpu_port)
 		return;
-	}
 
 	/* On the RTL9300 for at least the RTL8226B PHY, the MAC-side link
 	 * state needs to be read twice in order to read a correct result.
 	 * This would not be necessary for ports connected e.g. to RTL8218D
 	 * PHYs.
 	 */
-	state->link = 0;
 	link = priv->r->get_port_reg_le(priv->r->mac_link_sts);
 	link = priv->r->get_port_reg_le(priv->r->mac_link_sts);
-	if (link & BIT_ULL(port))
-		state->link = 1;
+	if (!(link & BIT_ULL(port)))
+		return;
+
+	state->link = 1;
 
 	if (priv->family_id == RTL9310_FAMILY_ID)
 		media = priv->r->get_port_reg_le(RTL931X_MAC_LINK_MEDIA_STS);
@@ -656,46 +660,37 @@ static void rtl93xx_pcs_get_state(struct phylink_pcs *pcs,
 	pr_debug("%s: link state port %d: %llx, media %llx\n", __func__, port,
 		 link & BIT_ULL(port), media);
 
-	state->duplex = 0;
 	if (priv->r->get_port_reg_le(priv->r->mac_link_dup_sts) & BIT_ULL(port))
-		state->duplex = 1;
+		state->duplex = DUPLEX_FULL;
+	else
+		state->duplex = DUPLEX_HALF;
 
 	speed = priv->r->get_port_reg_le(priv->r->mac_link_spd_sts(port));
-	speed >>= (port % 8) << 2;
-	switch (speed & 0xf) {
-	case 0:
+	speed = (speed >> ((port % 8) << 2)) & 0xf;
+	switch (speed) {
+	case RTL_SPEED_10:
 		state->speed = SPEED_10;
 		break;
-	case 1:
+	case RTL_SPEED_100:
 		state->speed = SPEED_100;
 		break;
-	case 2:
-	case 7:
+	case RTL_SPEED_1000:
 		state->speed = SPEED_1000;
 		break;
-	case 4:
+	case RTL_SPEED_10000:
 		state->speed = SPEED_10000;
 		break;
-	case 5:
-	case 8:
+	case RTL_SPEED_2500:
 		state->speed = SPEED_2500;
 		break;
-	case 6:
+	case RTL_SPEED_5000:
 		state->speed = SPEED_5000;
 		break;
 	default:
 		pr_err("%s: unknown speed: %d\n", __func__, (u32)speed & 0xf);
 	}
 
-	if (priv->family_id == RTL9310_FAMILY_ID
-		&& (port >= 52 && port <= 55)) { /* Internal serdes */
-			state->speed = SPEED_10000;
-			state->link = 1;
-			state->duplex = 1;
-	}
-
 	pr_debug("%s: speed is: %d %d\n", __func__, (u32)speed & 0xf, state->speed);
-	state->pause &= (MLO_PAUSE_RX | MLO_PAUSE_TX);
 	if (priv->r->get_port_reg_le(priv->r->mac_rx_pause_sts) & BIT_ULL(port))
 		state->pause |= MLO_PAUSE_RX;
 	if (priv->r->get_port_reg_le(priv->r->mac_tx_pause_sts) & BIT_ULL(port))
@@ -2750,7 +2745,7 @@ const struct dsa_switch_ops rtl83xx_switch_ops = {
 
 const struct phylink_pcs_ops rtl93xx_pcs_ops = {
 	.pcs_an_restart		= rtl83xx_pcs_an_restart,
-	.pcs_get_state		= rtl93xx_pcs_get_state,
+	.pcs_get_state		= rtldsa_93xx_pcs_get_state,
 	.pcs_config		= rtl83xx_pcs_config,
 };