[PATCH net-next v2 1/3] net: phy: enable interrupts when PHY is attached already

[Heiner Kallweit <hkallweit1@gmail.com>]

This patch is a step towards allowing PHY drivers to handle more
interrupt sources than just link change. E.g. several PHY's have
built-in temperature monitoring and can raise an interrupt if a
temperature threshold is exceeded. We may be interested in such
interrupts also if the phylib state machine isn't started.
Therefore move enabling interrupts to phy_request_interrupt().

v2:
- patch added to series

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 drivers/net/phy/phy.c        | 36 ++++++++++++++++++++++--------------
 drivers/net/phy/phy_device.c |  2 +-
 include/linux/phy.h          |  1 +
 3 files changed, 24 insertions(+), 15 deletions(-)

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index e88854292..d90d9863e 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -799,10 +799,10 @@ static int phy_enable_interrupts(struct phy_device *phydev)
 }
 
 /**
- * phy_request_interrupt - request interrupt for a PHY device
+ * phy_request_interrupt - request and enable interrupt for a PHY device
  * @phydev: target phy_device struct
  *
- * Description: Request the interrupt for the given PHY.
+ * Description: Request and enable the interrupt for the given PHY.
  *   If this fails, then we set irq to PHY_POLL.
  *   This should only be called with a valid IRQ number.
  */
@@ -817,10 +817,30 @@ void phy_request_interrupt(struct phy_device *phydev)
 		phydev_warn(phydev, "Error %d requesting IRQ %d, falling back to polling\n",
 			    err, phydev->irq);
 		phydev->irq = PHY_POLL;
+	} else {
+		if (phy_enable_interrupts(phydev)) {
+			phydev_warn(phydev, "Can't enable interrupt, falling back to polling\n");
+			phy_free_interrupt(phydev);
+			phydev->irq = PHY_POLL;
+		}
 	}
 }
 EXPORT_SYMBOL(phy_request_interrupt);
 
+/**
+ * phy_free_interrupt - disable and free interrupt for a PHY device
+ * @phydev: target phy_device struct
+ *
+ * Description: Disable and free the interrupt for the given PHY.
+ *   This should only be called with a valid IRQ number.
+ */
+void phy_free_interrupt(struct phy_device *phydev)
+{
+	phy_disable_interrupts(phydev);
+	free_irq(phydev->irq, phydev);
+}
+EXPORT_SYMBOL(phy_free_interrupt);
+
 /**
  * phy_stop - Bring down the PHY link, and stop checking the status
  * @phydev: target phy_device struct
@@ -835,9 +855,6 @@ void phy_stop(struct phy_device *phydev)
 
 	mutex_lock(&phydev->lock);
 
-	if (phy_interrupt_is_valid(phydev))
-		phy_disable_interrupts(phydev);
-
 	phydev->state = PHY_HALTED;
 
 	mutex_unlock(&phydev->lock);
@@ -864,8 +881,6 @@ EXPORT_SYMBOL(phy_stop);
  */
 void phy_start(struct phy_device *phydev)
 {
-	int err;
-
 	mutex_lock(&phydev->lock);
 
 	if (phydev->state != PHY_READY && phydev->state != PHY_HALTED) {
@@ -877,13 +892,6 @@ void phy_start(struct phy_device *phydev)
 	/* if phy was suspended, bring the physical link up again */
 	__phy_resume(phydev);
 
-	/* make sure interrupts are enabled for the PHY */
-	if (phy_interrupt_is_valid(phydev)) {
-		err = phy_enable_interrupts(phydev);
-		if (err < 0)
-			goto out;
-	}
-
 	phydev->state = PHY_UP;
 
 	phy_start_machine(phydev);
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 5d288da9a..d71b3ed52 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -1013,7 +1013,7 @@ void phy_disconnect(struct phy_device *phydev)
 		phy_stop(phydev);
 
 	if (phy_interrupt_is_valid(phydev))
-		free_irq(phydev->irq, phydev);
+		phy_free_interrupt(phydev);
 
 	phydev->adjust_link = NULL;
 
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 7180b1d1e..72e1196f9 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -1147,6 +1147,7 @@ int phy_ethtool_ksettings_set(struct phy_device *phydev,
 			      const struct ethtool_link_ksettings *cmd);
 int phy_mii_ioctl(struct phy_device *phydev, struct ifreq *ifr, int cmd);
 void phy_request_interrupt(struct phy_device *phydev);
+void phy_free_interrupt(struct phy_device *phydev);
 void phy_print_status(struct phy_device *phydev);
 int phy_set_max_speed(struct phy_device *phydev, u32 max_speed);
 void phy_remove_link_mode(struct phy_device *phydev, u32 link_mode);
-- 
2.21.0