[SRU][R][PATCH 4/7] UBUNTU: SAUCE: r8169: fix RTL8116af link readiness bug

[AceLan Kao]

From: Javen Xu <javen_xu at realsil.com.cn>

BugLink: https://bugs.launchpad.net/bugs/2160475

For saving power, RTL8116af can not read link status from standard phy
register. Instead, we should read link status through mac register.

Signed-off-by: Javen Xu <javen_xu at realsil.com.cn>
(cherry picked from commit https://lore.kernel.org/netdev/20260603065916.334-4-javen_xu@realsil.com.cn/)
Signed-off-by: Chia-Lin Kao (AceLan) <acelan.kao at canonical.com>
---
 drivers/net/ethernet/realtek/r8169_main.c | 73 +++++++++++++++++++----
 1 file changed, 61 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
index fb416c77ca5b..a0f76cac4cad 100644
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -451,6 +451,12 @@ enum rtl8125_registers {
 
 #define RX_FETCH_DFLT_8125	(8 << 27)
 
+#define OCP_SDS_ADDR_REG	0xEB10
+#define OCP_SDS_CMD_REG		0xEB0E
+#define OCP_SDS_DATA_REG	0xEB14
+#define SDS_CMD_READ		0x0001
+#define RTL_SDS_C22_BASE	0x40
+
 enum rtl_register_content {
 	/* InterruptStatusBits */
 	SYSErr		= 0x8000,
@@ -725,6 +731,12 @@ enum rtl_dash_type {
 	RTL_DASH_25_BP,
 };
 
+enum rtl_sfp_mode {
+	RTL_SFP_NONE,
+	RTL_SFP_8116_AF,
+	RTL_SFP_8127_ATF,
+};
+
 struct rtl8169_private {
 	void __iomem *mmio_addr;	/* memory map physical address */
 	struct pci_dev *pci_dev;
@@ -733,6 +745,7 @@ struct rtl8169_private {
 	struct napi_struct napi;
 	enum mac_version mac_version;
 	enum rtl_dash_type dash_type;
+	enum rtl_sfp_mode sfp_mode;
 	u32 cur_rx; /* Index into the Rx descriptor buffer of next Rx pkt. */
 	u32 cur_tx; /* Index into the Tx descriptor buffer of next Rx pkt. */
 	u32 dirty_tx;
@@ -759,7 +772,6 @@ struct rtl8169_private {
 	unsigned supports_gmii:1;
 	unsigned aspm_manageable:1;
 	unsigned dash_enabled:1;
-	bool sfp_mode:1;
 	dma_addr_t counters_phys_addr;
 	struct rtl8169_counters *counters;
 	struct rtl8169_tc_offsets tc_offset;
@@ -1191,13 +1203,42 @@ static u16 r8168_mac_ocp_read(struct rtl8169_private *tp, u32 reg)
 	return val;
 }
 
+static u16 rtl8116af_sds_read(struct rtl8169_private *tp, u16 sds_reg)
+{
+	r8168_mac_ocp_write(tp, OCP_SDS_ADDR_REG, sds_reg);
+	r8168_mac_ocp_write(tp, OCP_SDS_CMD_REG, SDS_CMD_READ);
+	return r8168_mac_ocp_read(tp, OCP_SDS_DATA_REG);
+}
+
+static bool rtl_is_8116af(struct rtl8169_private *tp)
+{
+	return tp->mac_version == RTL_GIGA_MAC_VER_52 &&
+		(r8168_mac_ocp_read(tp, 0xdc00) & 0x0078) == 0x0030 &&
+		(r8168_mac_ocp_read(tp, 0xd006) & 0x00ff) == 0x0000;
+}
+
 static int r8168_phy_ocp_read(struct rtl8169_private *tp, u32 reg)
 {
 	if (rtl_ocp_reg_failure(reg))
 		return 0;
 
+	if (tp->sfp_mode == RTL_SFP_8116_AF) {
+		switch (reg) {
+		case OCP_STD_PHY_BASE + 2 * MII_PHYSID1:
+			return upper_16_bits(PHY_ID_RTL8116AF_DUMMY);
+		case OCP_STD_PHY_BASE + 2 * MII_PHYSID2:
+			return lower_16_bits(PHY_ID_RTL8116AF_DUMMY);
+		case OCP_STD_PHY_BASE + 2 * MII_BMSR:
+			return rtl8116af_sds_read(tp, RTL_SDS_C22_BASE + MII_BMSR);
+		case OCP_STD_PHY_BASE + 2 * MII_BMCR:
+			return rtl8116af_sds_read(tp, RTL_SDS_C22_BASE + MII_BMCR);
+		default:
+			break;
+		}
+	}
+
 	/* Return dummy MII_PHYSID2 in SFP mode to match SFP PHY driver */
-	if (tp->sfp_mode && reg == (OCP_STD_PHY_BASE + 2 * MII_PHYSID2))
+	if (tp->sfp_mode == RTL_SFP_8127_ATF && reg == (OCP_STD_PHY_BASE + 2 * MII_PHYSID2))
 		return PHY_ID_RTL_DUMMY_SFP & 0xffff;
 
 	RTL_W32(tp, GPHY_OCP, reg << 15);
@@ -1574,6 +1615,20 @@ static bool rtl_dash_is_enabled(struct rtl8169_private *tp)
 	}
 }
 
+static enum rtl_sfp_mode rtl_get_sfp_mode(struct rtl8169_private *tp)
+{
+	if (rtl_is_8125(tp)) {
+		u16 data = r8168_mac_ocp_read(tp, 0xd006);
+
+		if ((data & 0xff) == 0x07)
+			return RTL_SFP_8127_ATF;
+	} else if (rtl_is_8116af(tp)) {
+		return RTL_SFP_8116_AF;
+	}
+
+	return RTL_SFP_NONE;
+}
+
 static enum rtl_dash_type rtl_get_dash_type(struct rtl8169_private *tp)
 {
 	switch (tp->mac_version) {
@@ -2390,7 +2445,7 @@ static int rtl8169_set_link_ksettings(struct net_device *ndev,
 	int duplex = cmd->base.duplex;
 	int speed = cmd->base.speed;
 
-	if (!tp->sfp_mode)
+	if (tp->sfp_mode != RTL_SFP_8127_ATF)
 		return phy_ethtool_ksettings_set(phydev, cmd);
 
 	if (cmd->base.autoneg != AUTONEG_DISABLE)
@@ -2548,7 +2603,7 @@ static void rtl8169_init_phy(struct rtl8169_private *tp)
 	    tp->pci_dev->subsystem_device == 0xe000)
 		phy_write_paged(tp->phydev, 0x0001, 0x10, 0xf01b);
 
-	if (tp->sfp_mode)
+	if (tp->sfp_mode == RTL_SFP_8127_ATF)
 		rtl_sfp_init(tp);
 
 	/* We may have called phy_speed_down before */
@@ -5004,7 +5059,7 @@ static void rtl8169_down(struct rtl8169_private *tp)
 	phy_stop(tp->phydev);
 
 	/* Reset SerDes PHY to bring down fiber link */
-	if (tp->sfp_mode)
+	if (tp->sfp_mode == RTL_SFP_8127_ATF)
 		rtl_sfp_reset(tp);
 
 	rtl8169_update_counters(tp);
@@ -5706,13 +5761,7 @@ static int rtl_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	}
 	tp->aspm_manageable = !rc;
 
-	if (rtl_is_8125(tp)) {
-		u16 data = r8168_mac_ocp_read(tp, 0xd006);
-
-		if ((data & 0xff) == 0x07)
-			tp->sfp_mode = true;
-	}
-
+	tp->sfp_mode = rtl_get_sfp_mode(tp);
 	tp->dash_type = rtl_get_dash_type(tp);
 	tp->dash_enabled = rtl_dash_is_enabled(tp);
 
-- 
2.53.0