kernel: net: phy: realtek: replace hack with proper fix

RealTek's 2.5G PHYs suffer from an up to now inexplicable problem which
results in the SerDes mode not being properly setup and disabling
in-band AN leading to a timeout waiting for a busy-bit to clear. Up to
now there has been a crude work-around: resetting the PHY and trying
another time.

The cause has now been found as a wrong access to register PHYCR1 on
MDIO_MMD_VEND1 instead of MDIO_MMD_VEND2 when setting up ALDPS as well
as disabling the MDIO broadcast address 0.

In order to access MDIO_MMD_VEND2 on Clause-22-only busses a custom
.read_mmd and .write_mmd ops are implemented, mapping MDIO_MMD_VEND2 to
paged access as this is required.

Also, as ALDPS by design disables the SerDes PCS of the PHY in case the
link has been down for a while, move enabling ALDPS to the end of the
config_init function to not face problems when configuring the interface
mode and in-band AN.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

Author: dangowrt

target/linux/generic/pending-6.12/720-04-net-phy-realtek-setup-aldps.patch

@@ -24,19 +24,68 @@ Signed-off-by: Daniel Golle <daniel@makrotopia.org>
  #define RTL8366RB_POWER_SAVE			0x15
  #define RTL8366RB_POWER_SAVE_ON			BIT(12)
 
-@@ -1090,6 +1094,15 @@ static int rtl822xb_config_init(struct p
+@@ -175,6 +179,10 @@ struct rtl821x_priv {
+ 	u32 saved_wolopts;
+ };
+ 
++struct rtl822x_priv {
++	bool enable_aldps;
++};
++
+ static int rtl821x_read_page(struct phy_device *phydev)
+ {
+ 	return __phy_read(phydev, RTL821x_PAGE_SELECT);
+@@ -1025,6 +1033,18 @@ static int rtl822x_write_mmd(struct phy_
+ 
+ static int rtl822x_probe(struct phy_device *phydev)
+ {
++	struct device *dev = &phydev->mdio.dev;
++	struct rtl822x_priv *priv;
++
++	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
++	if (!priv)
++		return -ENOMEM;
++
++	priv->enable_aldps = of_property_read_bool(dev->of_node,
++						   "realtek,aldps-enable");
++
++	phydev->priv = priv;
++
+ 	if (IS_ENABLED(CONFIG_REALTEK_PHY_HWMON) &&
+ 	    phydev->phy_id != RTL_GENERIC_PHYID)
+ 		return rtl822x_hwmon_init(phydev);
+@@ -1032,6 +1052,19 @@ static int rtl822x_probe(struct phy_devi
+ 	return 0;
+ }
+ 
++static int rtl822x_init_phycr1(struct phy_device *phydev, bool no_aldps)
++{
++	struct rtl822x_priv *priv = phydev->priv;
++	u16 val = 0;
++
++	if (priv->enable_aldps && !no_aldps)
++		val = RTL8221B_PHYCR1_ALDPS_EN | RTL8221B_PHYCR1_ALDPS_XTAL_OFF_EN;
++
++	return phy_modify_mmd_changed(phydev, MDIO_MMD_VEND2, RTL8221B_PHYCR1,
++				      RTL8221B_PHYCR1_ALDPS_EN |
++				      RTL8221B_PHYCR1_ALDPS_XTAL_OFF_EN, val);
++}
++
+ static int rtl822xb_config_init(struct phy_device *phydev)
+ {
+ 	bool has_2500, has_sgmii;
+@@ -1108,6 +1141,14 @@ static int rtl822xb_config_init(struct p
  	if (ret < 0)
  		return ret;
 
-+	if (of_property_read_bool(phydev->mdio.dev.of_node, "realtek,aldps-enable"))
-+		ret = phy_set_bits_mmd(phydev, MDIO_MMD_VEND1, RTL8221B_PHYCR1,
-+				 RTL8221B_PHYCR1_ALDPS_EN | RTL8221B_PHYCR1_ALDPS_XTAL_OFF_EN);
-+	else
-+		ret = phy_clear_bits_mmd(phydev, MDIO_MMD_VEND1, RTL8221B_PHYCR1,
-+				   RTL8221B_PHYCR1_ALDPS_EN | RTL8221B_PHYCR1_ALDPS_XTAL_OFF_EN);
++	ret = phy_write_mmd(phydev, MDIO_MMD_VEND1, 0x6f11, 0x8020);
 +	if (ret < 0)
 +		return ret;
 +
- 	/* Disable SGMII AN */
- 	ret = phy_write_mmd(phydev, MDIO_MMD_VEND1, 0x7588, 0x2);
- 	if (ret < 0)
++	ret = rtl822x_init_phycr1(phydev, false);
++	if (ret < 0)
++		return ret;
++
+ 	return 0;
+ }
+ 

target/linux/generic/pending-6.12/720-08-net-phy-realtek-work-around-broken-serdes.patch

@@ -13,15 +13,21 @@ Signed-off-by: Daniel Golle <daniel@makrotopia.org>
 ---
 --- a/drivers/net/phy/realtek/realtek_main.c
 +++ b/drivers/net/phy/realtek/realtek_main.c
-@@ -1050,6 +1050,11 @@ static int rtl822xb_config_init(struct p
- 			     phydev->host_interfaces) ||
- 		    phydev->interface == PHY_INTERFACE_MODE_SGMII;
+@@ -132,6 +132,7 @@
+ #define RTL8221B_PHYCR1				0xa430
+ #define RTL8221B_PHYCR1_ALDPS_EN		BIT(2)
+ #define RTL8221B_PHYCR1_ALDPS_XTAL_OFF_EN	BIT(12)
++#define RTL8221B_PHYCR1_PHYAD_0_EN		BIT(13)
 
-+	/* disable listening on MDIO broadcast address (0) */
-+	ret = phy_clear_bits_mmd(phydev, MDIO_MMD_VEND2, 0xa430, BIT(13));
-+	if (ret < 0)
-+		return ret;
-+
- 	/* fill in possible interfaces */
- 	__assign_bit(PHY_INTERFACE_MODE_2500BASEX, phydev->possible_interfaces,
- 		     has_2500);
+ #define RTL8366RB_POWER_SAVE			0x15
+ #define RTL8366RB_POWER_SAVE_ON			BIT(12)
+@@ -1062,7 +1063,8 @@ static int rtl822x_init_phycr1(struct ph
+ 
+ 	return phy_modify_mmd_changed(phydev, MDIO_MMD_VEND2, RTL8221B_PHYCR1,
+ 				      RTL8221B_PHYCR1_ALDPS_EN |
+-				      RTL8221B_PHYCR1_ALDPS_XTAL_OFF_EN, val);
++				      RTL8221B_PHYCR1_ALDPS_XTAL_OFF_EN |
++				      RTL8221B_PHYCR1_PHYAD_0_EN, val);
+ }
+ 
+ static int rtl822xb_config_init(struct phy_device *phydev)

target/linux/generic/pending-6.12/720-09-net-phy-realtek-disable-MDIO-broadcast.patch

@@ -24,19 +24,68 @@ Signed-off-by: Daniel Golle <daniel@makrotopia.org>
  #define RTL8366RB_POWER_SAVE			0x15
  #define RTL8366RB_POWER_SAVE_ON			BIT(12)
 
-@@ -1090,6 +1094,15 @@ static int rtl822xb_config_init(struct p
+@@ -175,6 +179,10 @@ struct rtl821x_priv {
+ 	u32 saved_wolopts;
+ };
+ 
++struct rtl822x_priv {
++	bool enable_aldps;
++};
++
+ static int rtl821x_read_page(struct phy_device *phydev)
+ {
+ 	return __phy_read(phydev, RTL821x_PAGE_SELECT);
+@@ -1025,6 +1033,18 @@ static int rtl822x_write_mmd(struct phy_
+ 
+ static int rtl822x_probe(struct phy_device *phydev)
+ {
++	struct device *dev = &phydev->mdio.dev;
++	struct rtl822x_priv *priv;
++
++	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
++	if (!priv)
++		return -ENOMEM;
++
++	priv->enable_aldps = of_property_read_bool(dev->of_node,
++						   "realtek,aldps-enable");
++
++	phydev->priv = priv;
++
+ 	if (IS_ENABLED(CONFIG_REALTEK_PHY_HWMON) &&
+ 	    phydev->phy_id != RTL_GENERIC_PHYID)
+ 		return rtl822x_hwmon_init(phydev);
+@@ -1032,6 +1052,19 @@ static int rtl822x_probe(struct phy_devi
+ 	return 0;
+ }
+ 
++static int rtl822x_init_phycr1(struct phy_device *phydev, bool no_aldps)
++{
++	struct rtl822x_priv *priv = phydev->priv;
++	u16 val = 0;
++
++	if (priv->enable_aldps && !no_aldps)
++		val = RTL8221B_PHYCR1_ALDPS_EN | RTL8221B_PHYCR1_ALDPS_XTAL_OFF_EN;
++
++	return phy_modify_mmd_changed(phydev, MDIO_MMD_VEND2, RTL8221B_PHYCR1,
++				      RTL8221B_PHYCR1_ALDPS_EN |
++				      RTL8221B_PHYCR1_ALDPS_XTAL_OFF_EN, val);
++}
++
+ static int rtl822xb_config_init(struct phy_device *phydev)
+ {
+ 	bool has_2500, has_sgmii;
+@@ -1108,6 +1141,14 @@ static int rtl822xb_config_init(struct p
  	if (ret < 0)
  		return ret;
 
-+	if (of_property_read_bool(phydev->mdio.dev.of_node, "realtek,aldps-enable"))
-+		ret = phy_set_bits_mmd(phydev, MDIO_MMD_VEND1, RTL8221B_PHYCR1,
-+				 RTL8221B_PHYCR1_ALDPS_EN | RTL8221B_PHYCR1_ALDPS_XTAL_OFF_EN);
-+	else
-+		ret = phy_clear_bits_mmd(phydev, MDIO_MMD_VEND1, RTL8221B_PHYCR1,
-+				   RTL8221B_PHYCR1_ALDPS_EN | RTL8221B_PHYCR1_ALDPS_XTAL_OFF_EN);
++	ret = phy_write_mmd(phydev, MDIO_MMD_VEND1, 0x6f11, 0x8020);
 +	if (ret < 0)
 +		return ret;
 +
- 	/* Disable SGMII AN */
- 	ret = phy_write_mmd(phydev, MDIO_MMD_VEND1, 0x7588, 0x2);
- 	if (ret < 0)
++	ret = rtl822x_init_phycr1(phydev, false);
++	if (ret < 0)
++		return ret;
++
+ 	return 0;
+ }
+ 

target/linux/generic/pending-6.6/720-04-net-phy-realtek-setup-aldps.patch

@@ -13,15 +13,21 @@ Signed-off-by: Daniel Golle <daniel@makrotopia.org>
 ---
 --- a/drivers/net/phy/realtek/realtek_main.c
 +++ b/drivers/net/phy/realtek/realtek_main.c
-@@ -1050,6 +1050,11 @@ static int rtl822xb_config_init(struct p
- 			     phydev->host_interfaces) ||
- 		    phydev->interface == PHY_INTERFACE_MODE_SGMII;
+@@ -132,6 +132,7 @@
+ #define RTL8221B_PHYCR1				0xa430
+ #define RTL8221B_PHYCR1_ALDPS_EN		BIT(2)
+ #define RTL8221B_PHYCR1_ALDPS_XTAL_OFF_EN	BIT(12)
++#define RTL8221B_PHYCR1_PHYAD_0_EN		BIT(13)
 
-+	/* disable listening on MDIO broadcast address (0) */
-+	ret = phy_clear_bits_mmd(phydev, MDIO_MMD_VEND2, 0xa430, BIT(13));
-+	if (ret < 0)
-+		return ret;
-+
- 	/* fill in possible interfaces */
- 	__assign_bit(PHY_INTERFACE_MODE_2500BASEX, phydev->possible_interfaces,
- 		     has_2500);
+ #define RTL8366RB_POWER_SAVE			0x15
+ #define RTL8366RB_POWER_SAVE_ON			BIT(12)
+@@ -1062,7 +1063,8 @@ static int rtl822x_init_phycr1(struct ph
+ 
+ 	return phy_modify_mmd_changed(phydev, MDIO_MMD_VEND2, RTL8221B_PHYCR1,
+ 				      RTL8221B_PHYCR1_ALDPS_EN |
+-				      RTL8221B_PHYCR1_ALDPS_XTAL_OFF_EN, val);
++				      RTL8221B_PHYCR1_ALDPS_XTAL_OFF_EN |
++				      RTL8221B_PHYCR1_PHYAD_0_EN, val);
+ }
+ 
+ static int rtl822xb_config_init(struct phy_device *phydev)