net: phy: constify phydev->drv

Device driver structures are shared between all devices that they
match, and thus nothing should never write to the device driver
structure through the phydev->drv pointer. Let's make this pointer
const to catch code that attempts to do so.

Suggested-by: Christian Marangi <[e-mail]>
Signed-off-by: Russell King (Oracle) <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Paolo Abeni <[e-mail]>

drivers/net/phy/phy.c

···
 static irqreturn_t phy_interrupt(int irq, void *phy_dat)
 {
 	struct phy_device *phydev = phy_dat;
-	struct phy_driver *drv = phydev->drv;
 	irqreturn_t ret;
 
 	/* Wakeup interrupts may occur during a system sleep transition.
···
 	}
 
 	mutex_lock(&phydev->lock);
-	ret = drv->handle_interrupt(phydev);
+	ret = phydev->drv->handle_interrupt(phydev);
 	mutex_unlock(&phydev->lock);
 
 	return ret;

drivers/net/phy/phy_device.c

···
 }
 EXPORT_SYMBOL(phy_sfp_probe);
 
-static bool phy_drv_supports_irq(struct phy_driver *phydrv)
+static bool phy_drv_supports_irq(const struct phy_driver *phydrv)
 {
 	return phydrv->config_intr && phydrv->handle_interrupt;
 }
···
 {
 	struct ethtool_wolinfo wol = { .cmd = ETHTOOL_GWOL };
 	struct net_device *netdev = phydev->attached_dev;
-	struct phy_driver *phydrv = phydev->drv;
+	const struct phy_driver *phydrv = phydev->drv;
 	int ret;
 
 	if (phydev->suspended)
···
 
 int __phy_resume(struct phy_device *phydev)
 {
-	struct phy_driver *phydrv = phydev->drv;
+	const struct phy_driver *phydrv = phydev->drv;
 	int ret;
 
 	lockdep_assert_held(&phydev->lock);

drivers/net/phy/xilinx_gmii2rgmii.c

···
 
 struct gmii2rgmii {
 	struct phy_device *phy_dev;
-	struct phy_driver *phy_drv;
+	const struct phy_driver *phy_drv;
 	struct phy_driver conv_phy_drv;
 	struct mdio_device *mdio;
 };

include/linux/phy.h

···
 
 	/* Information about the PHY type */
 	/* And management functions */
-	struct phy_driver *drv;
+	const struct phy_driver *drv;
 
 	struct device_link *devlink;