openwrt/target/linux/generic/backport-6.6/781-20-v6.14-net-phy-realtek-clear-1000Base-T-lpa-if-link-is-down.patch

From 34d5a86ff7bbe225fba3ad91f9b4dc85fb408e18 Mon Sep 17 00:00:00 2001
From: Daniel Golle <daniel@makrotopia.org>
Date: Wed, 15 Jan 2025 14:43:35 +0000
Subject: [PATCH] net: phy: realtek: clear 1000Base-T lpa if link is down

Only read 1000Base-T link partner advertisement if autonegotiation has
completed and otherwise 1000Base-T link partner advertisement bits.

This fixes bogus 1000Base-T link partner advertisement after link goes
down (eg. by disconnecting the wire).
Fixes: 5cb409b3960e ("net: phy: realtek: clear 1000Base-T link partner advertisement")
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 drivers/net/phy/realtek.c | 19 ++++++++-----------
 1 file changed, 8 insertions(+), 11 deletions(-)

--- a/drivers/net/phy/realtek.c
+++ b/drivers/net/phy/realtek.c
@@ -1023,23 +1023,20 @@ static int rtl822x_c45_read_status(struc
 {
 	int ret, val;
 
-	ret = genphy_c45_read_status(phydev);
-	if (ret < 0)
-		return ret;
-
-	if (phydev->autoneg == AUTONEG_DISABLE ||
-	    !genphy_c45_aneg_done(phydev))
-		mii_stat1000_mod_linkmode_lpa_t(phydev->lp_advertising, 0);
-
 	/* Vendor register as C45 has no standardized support for 1000BaseT */
-	if (phydev->autoneg == AUTONEG_ENABLE) {
+	if (phydev->autoneg == AUTONEG_ENABLE && genphy_c45_aneg_done(phydev)) {
 		val = phy_read_mmd(phydev, MDIO_MMD_VEND2,
 				   RTL822X_VND2_GANLPAR);
 		if (val < 0)
 			return val;
-
-		mii_stat1000_mod_linkmode_lpa_t(phydev->lp_advertising, val);
+	} else {
+		val = 0;
 	}
+	mii_stat1000_mod_linkmode_lpa_t(phydev->lp_advertising, val);
+
+	ret = genphy_c45_read_status(phydev);
+	if (ret < 0)
+		return ret;
 
 	if (!phydev->link)
 		return 0;