net: phy: meson-gxl: fix interrupt handling in forced mode

This PHY doesn't support a link-up interrupt source. If aneg is enabled
we use the "aneg complete" interrupt for this purpose, but if aneg is
disabled link-up isn't signaled currently.
According to a vendor driver there's an additional "energy detect"
interrupt source that can be used to signal link-up if aneg is disabled.
We can safely ignore this interrupt source if aneg is enabled.

This patch was tested on a TX3 Mini TV box with S905W (even though
boot message says it's a S905D).

This issue has been existing longer, but due to changes in phylib and
the driver the patch applies only from the commit marked as fixed.

Fixes: 84c8f773 ("net: phy: meson-gxl: remove the use of .ack_callback()")
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/04cac530-ea1b-850e-6cfa-144a55c4d75d@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/phy/meson-gxl.c

@@ -30,8 +30,12 @@
 #define  INTSRC_LINK_DOWN	BIT(4)
 #define  INTSRC_REMOTE_FAULT	BIT(5)
 #define  INTSRC_ANEG_COMPLETE	BIT(6)
+#define  INTSRC_ENERGY_DETECT	BIT(7)
 #define INTSRC_MASK	30
 
+#define INT_SOURCES (INTSRC_LINK_DOWN | INTSRC_ANEG_COMPLETE | \
+		     INTSRC_ENERGY_DETECT)
+
 #define BANK_ANALOG_DSP		0
 #define BANK_WOL		1
 #define BANK_BIST		3
@@ -200,7 +204,6 @@ static int meson_gxl_ack_interrupt(struct phy_device *phydev)
 
 static int meson_gxl_config_intr(struct phy_device *phydev)
 {
-	u16 val;
 	int ret;
 
 	if (phydev->interrupts == PHY_INTERRUPT_ENABLED) {
@@ -209,16 +212,9 @@ static int meson_gxl_config_intr(struct phy_device *phydev)
 		if (ret)
 			return ret;
 
-		val = INTSRC_ANEG_PR
-			| INTSRC_PARALLEL_FAULT
-			| INTSRC_ANEG_LP_ACK
-			| INTSRC_LINK_DOWN
-			| INTSRC_REMOTE_FAULT
-			| INTSRC_ANEG_COMPLETE;
-		ret = phy_write(phydev, INTSRC_MASK, val);
+		ret = phy_write(phydev, INTSRC_MASK, INT_SOURCES);
 	} else {
-		val = 0;
-		ret = phy_write(phydev, INTSRC_MASK, val);
+		ret = phy_write(phydev, INTSRC_MASK, 0);
 
 		/* Ack any pending IRQ */
 		ret = meson_gxl_ack_interrupt(phydev);
@@ -237,9 +233,16 @@ static irqreturn_t meson_gxl_handle_interrupt(struct phy_device *phydev)
 		return IRQ_NONE;
 	}
 
+	irq_status &= INT_SOURCES;
+
 	if (irq_status == 0)
 		return IRQ_NONE;
 
+	/* Aneg-complete interrupt is used for link-up detection */
+	if (phydev->autoneg == AUTONEG_ENABLE &&
+	    irq_status == INTSRC_ENERGY_DETECT)
+		return IRQ_HANDLED;
+
 	phy_trigger_machine(phydev);
 
 	return IRQ_HANDLED;