[PATCH net v4] net: phy: marvell: keep WOL_EIE across interrupt reconfiguration

[Rosen Penev <rosenp@gmail.com>]

marvell_config_intr() rewrote the whole interrupt enable register, so
the config_intr call from phy_init_hw() on resume silently cleared
WOL_EIE on the 88E1318S and 88E1510: m88e1318_get_wol() still reported
WAKE_MAGIC, but a matched magic packet was no longer routed to INTn and
the board did not wake.

Make config_intr update every bit except WOL_EIE with phy_modify(), so
the WoL interrupt enable is owned only by set_wol and always matches
what it programmed. The read-modify-write runs under the MDIO bus lock,
as do the accesses in m88e1318_set_wol(), so the two can no longer
overwrite each other's update. Have m88e1318_set_wol() clear WOL_EIE
when WoL is fully disabled, since config_intr no longer does.

The interrupt register layout is the same across the PHYs this driver
handles, so extend the shared handler to also claim a WoL event instead
of adding a per-PHY one.

Fixes: 3871c3876f80 ("mv643xx_eth with 88E1318S: support Wake on LAN")
Assisted-by: LLM
Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 v4: remove MII_88E1318S_PHY_CSIER_ defines.
 v3: use phy_modify()
 v2: resolved review warnings, including wol d.
 drivers/net/phy/marvell.c | 39 +++++++++++++++++++++++++++------------
 1 file changed, 27 insertions(+), 12 deletions(-)

diff --git a/drivers/net/phy/marvell.c b/drivers/net/phy/marvell.c
index f71cffa88406..5f9a43a4a063 100644
--- a/drivers/net/phy/marvell.c
+++ b/drivers/net/phy/marvell.c
@@ -55,6 +55,12 @@
 #define MII_M1011_IMASK			0x12
 #define MII_M1011_IMASK_INIT		0x6400
 #define MII_M1011_IMASK_CLEAR		0x0000
+#define MII_M1011_IMASK_WOL		BIT(7)
+/* Bits updated by config_intr. The WoL interrupt enable is owned by
+ * set_wol, so the config_intr call from phy_init_hw() on resume does not
+ * silently disarm Wake-on-LAN.
+ */
+#define MII_M1011_IMASK_CONFIG_MASK	(U16_MAX & ~MII_M1011_IMASK_WOL)
 
 #define MII_M1011_PHY_SCR			0x10
 #define MII_M1011_PHY_SCR_DOWNSHIFT_EN		BIT(11)
@@ -139,11 +145,6 @@
 #define MII_88E1318S_PHY_MSCR1_REG	16
 #define MII_88E1318S_PHY_MSCR1_PAD_ODD	BIT(6)
 
-/* Copper Specific Interrupt Enable Register */
-#define MII_88E1318S_PHY_CSIER				0x12
-/* WOL Event Interrupt Enable */
-#define MII_88E1318S_PHY_CSIER_WOL_EIE			BIT(7)
-
 #define MII_88E1318S_PHY_LED_FUNC		0x10
 #define MII_88E1318S_PHY_LED_FUNC_OFF		(0x8)
 #define MII_88E1318S_PHY_LED_FUNC_ON		(0x9)
@@ -393,11 +394,13 @@ static int marvell_config_intr(struct phy_device *phydev)
 		if (err)
 			return err;
 
-		err = phy_write(phydev, MII_M1011_IMASK,
-				MII_M1011_IMASK_INIT);
+		err = phy_modify(phydev, MII_M1011_IMASK,
+				 MII_M1011_IMASK_CONFIG_MASK,
+				 MII_M1011_IMASK_INIT);
 	} else {
-		err = phy_write(phydev, MII_M1011_IMASK,
-				MII_M1011_IMASK_CLEAR);
+		err = phy_modify(phydev, MII_M1011_IMASK,
+				 MII_M1011_IMASK_CONFIG_MASK,
+				 MII_M1011_IMASK_CLEAR);
 		if (err)
 			return err;
 
@@ -417,7 +420,7 @@ static irqreturn_t marvell_handle_interrupt(struct phy_device *phydev)
 		return IRQ_NONE;
 	}
 
-	if (!(irq_status & MII_M1011_IMASK_INIT))
+	if (!(irq_status & (MII_M1011_IMASK_INIT | MII_M1011_IMASK_WOL)))
 		return IRQ_NONE;
 
 	phy_trigger_machine(phydev);
@@ -1991,8 +1994,8 @@ static int m88e1318_set_wol(struct phy_device *phydev,
 			__phy_read(phydev, MII_M1011_IEVENT);
 
 		/* Enable the WOL interrupt */
-		err = __phy_set_bits(phydev, MII_88E1318S_PHY_CSIER,
-				     MII_88E1318S_PHY_CSIER_WOL_EIE);
+		err = __phy_set_bits(phydev, MII_M1011_IMASK,
+				     MII_M1011_IMASK_WOL);
 		if (err < 0)
 			goto error;
 
@@ -2074,6 +2077,18 @@ static int m88e1318_set_wol(struct phy_device *phydev,
 			goto error;
 	}
 
+	if (!(wol->wolopts & (WAKE_MAGIC | WAKE_PHY))) {
+		err = marvell_write_page(phydev, MII_MARVELL_COPPER_PAGE);
+		if (err < 0)
+			goto error;
+
+		/* Disable the WOL interrupt, config_intr leaves it alone */
+		err = __phy_clear_bits(phydev, MII_M1011_IMASK,
+				       MII_M1011_IMASK_WOL);
+		if (err < 0)
+			goto error;
+	}
+
 error:
 	return phy_restore_page(phydev, oldpage, err);
 }
-- 
2.56.0