phy: fix the use of PHY_IGNORE_INTERRUPT

When a PHY device is registered with the special IRQ value
PHY_IGNORE_INTERRUPT (-2) it will not properly be handled by the PHY
library:

- it continues to poll its register, while we do not want this
  because such PHY link events or register changes are serviced by an
  Ethernet MAC
- it will still try to configure PHY interrupts at the PHY level, such
  interrupts do not exist at the PHY but at the MAC level
- the state machine only handles PHY_POLL, but should also handle
  PHY_IGNORE_INTERRUPT similarly

This patch updates the PHY state machine and initialization paths to
account for the specific PHY_IGNORE_INTERRUPT. Based on an earlier patch
by Thomas Petazzoni, and reworked to add the missing bits. Add a helper
phy_interrupt_is_valid() which specifically tests for a PHY interrupt
not to be PHY_POLL or PHY_IGNORE_INTERRUPT and use it throughout the
code.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 12 insertions, 0 deletions

diff --git a/include/linux/phy.h b/include/linux/phy.h
index 9e11039dd7a3..8e4bc8ab692d 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -508,6 +508,18 @@ static inline int phy_write(struct phy_device *phydev, u32 regnum, u16 val)
 	return mdiobus_write(phydev->bus, phydev->addr, regnum, val);
 }
 
+/**
+ * phy_interrupt_is_valid - Convenience function for testing a given PHY irq
+ * @phydev: the phy_device struct
+ *
+ * NOTE: must be kept in sync with addition/removal of PHY_POLL and
+ * PHY_IGNORE_INTERRUPT
+ */
+static inline bool phy_interrupt_is_valid(struct phy_device *phydev)
+{
+	return phydev->irq != PHY_POLL && phydev->irq != PHY_IGNORE_INTERRUPT;
+}
+
 struct phy_device *phy_device_create(struct mii_bus *bus, int addr, int phy_id,
 		bool is_c45, struct phy_c45_device_ids *c45_ids);
 struct phy_device *get_phy_device(struct mii_bus *bus, int addr, bool is_c45);