[PATCH net v12 1/4] net: usb: lan78xx: register the PHY interrupt with the MDIO bus

[Aleksei Sviridkin <f@lex.la>]

The interrupt this driver maps for its PHY is written only into
phydev->irq, while the bus table mdiobus->irq[] keeps reading PHY_POLL
for the same address. That table is where phylib records what the bus
described - phy_device_create() seeds phydev->irq from it - so the
number lives only as long as nothing else writes that one field.

Put it in the table before the bus is registered, so that the PHY the
scan creates is born with the number, and drop the write to phydev->irq
that phylib then makes by itself. Fill the whole table rather than one
entry: for 7801 the address is not known until the scan, and for the
other two phy_mask leaves only address 1 readable, so a loop costs less
than a second switch on the chip id. A devicetree PHY node that
describes an interrupt now overrides that, where the driver's number
used to win.

Found going through the drivers that keep a PHY interrupt outside the
bus table, so that the restore on detach later in this series has a
number to hand back here as well.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Assisted-by: LLM
Signed-off-by: Aleksei Sviridkin <f@lex.la>
---

Notes:
    v12: no change.
    
    Compile-tested only; I have no LAN78xx device. No Fixes: tag, since
    nothing reads the bus table back until patch 3.

 drivers/net/usb/lan78xx.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index 5655941f1478..522fb4daeb46 100644
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -2092,6 +2092,7 @@ static int lan78xx_mdio_init(struct lan78xx_net *dev)
 {
 	struct device_node *node;
 	int ret;
+	int i;
 
 	dev->mdiobus = mdiobus_alloc();
 	if (!dev->mdiobus) {
@@ -2118,6 +2119,10 @@ static int lan78xx_mdio_init(struct lan78xx_net *dev)
 		break;
 	}
 
+	if (dev->domain_data.phyirq > 0)
+		for (i = 0; i < PHY_MAX_ADDR; i++)
+			dev->mdiobus->irq[i] = dev->domain_data.phyirq;
+
 	node = of_get_child_by_name(dev->udev->dev.of_node, "mdio");
 	ret = of_mdiobus_register(dev->mdiobus, node);
 	of_node_put(node);
@@ -2892,13 +2897,6 @@ static int lan78xx_phy_init(struct lan78xx_net *dev)
 		return 0;
 	}
 
-	/* if phyirq is not set, use polling mode in phylib */
-	if (dev->domain_data.phyirq > 0)
-		phydev->irq = dev->domain_data.phyirq;
-	else
-		phydev->irq = PHY_POLL;
-	netdev_dbg(dev->net, "phydev->irq = %d\n", phydev->irq);
-
 	ret = phylink_connect_phy(dev->phylink, phydev);
 	if (ret) {
 		netdev_err(dev->net, "can't attach PHY to %s, error %pe\n",
-- 
2.53.0