net: phy: realtek: Dummy IRQ calls for RTL8366RB

This fixes a regression introduced by
commit 0d2e778e
"net: phy: replace PHY_HAS_INTERRUPT with a check for
config_intr and ack_interrupt".

This assumes that a PHY cannot trigger interrupt unless
it has .config_intr() or .ack_interrupt() implemented.
A later patch makes the code assume both need to be
implemented for interrupts to be present.

But this PHY (which is inside a DSA) will happily
fire interrupts without either callback.

Implement dummy callbacks for .config_intr() and
.ack_interrupt() in the phy header to fix this.

Tested on the RTL8366RB on D-Link DIR-685.

Fixes: 0d2e778e ("net: phy: replace PHY_HAS_INTERRUPT with a check for config_intr and ack_interrupt")
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/realtek.c

@@ -282,6 +282,13 @@ static struct phy_driver realtek_drvs[] = {
 		.name		= "RTL8366RB Gigabit Ethernet",
 		.features	= PHY_GBIT_FEATURES,
 		.config_init	= &rtl8366rb_config_init,
+		/* These interrupts are handled by the irq controller
+		 * embedded inside the RTL8366RB, they get unmasked when the
+		 * irq is requested and ACKed by reading the status register,
+		 * which is done by the irqchip code.
+		 */
+		.ack_interrupt	= genphy_no_ack_interrupt,
+		.config_intr	= genphy_no_config_intr,
 		.suspend	= genphy_suspend,
 		.resume		= genphy_resume,
 	},

include/linux/phy.h

@@ -992,6 +992,14 @@ static inline int genphy_no_soft_reset(struct phy_device *phydev)
 {
 	return 0;
 }
+static inline int genphy_no_ack_interrupt(struct phy_device *phydev)
+{
+	return 0;
+}
+static inline int genphy_no_config_intr(struct phy_device *phydev)
+{
+	return 0;
+}
 int genphy_read_mmd_unsupported(struct phy_device *phdev, int devad,
 				u16 regnum);
 int genphy_write_mmd_unsupported(struct phy_device *phdev, int devnum,