Merge branch 'net-phy-register-modifying-helpers'

Heiner Kallweit says:

====================
net: phy: add and use register modifying helpers returning 1 on change

Add and use register modifying helpers returning 1 on change.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 149 insertions, 46 deletions

diff --git a/drivers/net/phy/marvell10g.c b/drivers/net/phy/marvell10g.c
index 96a79c6c7810..08362dc657cd 100644
--- a/drivers/net/phy/marvell10g.c
+++ b/drivers/net/phy/marvell10g.c
@@ -141,10 +141,9 @@ static int mv3310_hwmon_config(struct phy_device *phydev, bool enable)
 		return ret;
 
 	val = enable ? MV_V2_TEMP_CTRL_SAMPLE : MV_V2_TEMP_CTRL_DISABLE;
-	ret = phy_modify_mmd(phydev, MDIO_MMD_VEND2, MV_V2_TEMP_CTRL,
-			     MV_V2_TEMP_CTRL_MASK, val);
 
-	return ret < 0 ? ret : 0;
+	return phy_modify_mmd(phydev, MDIO_MMD_VEND2, MV_V2_TEMP_CTRL,
+			      MV_V2_TEMP_CTRL_MASK, val);
 }
 
 static void mv3310_hwmon_disable(void *data)
@@ -345,7 +344,7 @@ static int mv3310_config_aneg(struct phy_device *phydev)
 	linkmode_and(phydev->advertising, phydev->advertising,
 		     phydev->supported);
 
-	ret = phy_modify_mmd(phydev, MDIO_MMD_AN, MDIO_AN_ADVERTISE,
+	ret = phy_modify_mmd_changed(phydev, MDIO_MMD_AN, MDIO_AN_ADVERTISE,
 			     ADVERTISE_ALL | ADVERTISE_100BASE4 |
 			     ADVERTISE_PAUSE_CAP | ADVERTISE_PAUSE_ASYM,
 			     linkmode_adv_to_mii_adv_t(phydev->advertising));
@@ -355,7 +354,7 @@ static int mv3310_config_aneg(struct phy_device *phydev)
 		changed = true;
 
 	reg = linkmode_adv_to_mii_ctrl1000_t(phydev->advertising);
-	ret = phy_modify_mmd(phydev, MDIO_MMD_AN, MV_AN_CTRL1000,
+	ret = phy_modify_mmd_changed(phydev, MDIO_MMD_AN, MV_AN_CTRL1000,
 			     ADVERTISE_1000FULL | ADVERTISE_1000HALF, reg);
 	if (ret < 0)
 		return ret;
@@ -369,8 +368,8 @@ static int mv3310_config_aneg(struct phy_device *phydev)
 	else
 		reg = 0;
 
-	ret = phy_modify_mmd(phydev, MDIO_MMD_AN, MDIO_AN_10GBT_CTRL,
-			     MDIO_AN_10GBT_CTRL_ADV10G, reg);
+	ret = phy_modify_mmd_changed(phydev, MDIO_MMD_AN, MDIO_AN_10GBT_CTRL,
+				     MDIO_AN_10GBT_CTRL_ADV10G, reg);
 	if (ret < 0)
 		return ret;
 	if (ret > 0)
diff --git a/drivers/net/phy/phy-core.c b/drivers/net/phy/phy-core.c
index 7d6aad287f84..cdea028d1328 100644
--- a/drivers/net/phy/phy-core.c
+++ b/drivers/net/phy/phy-core.c
@@ -531,7 +531,7 @@ int phy_write_mmd(struct phy_device *phydev, int devad, u32 regnum, u16 val)
 EXPORT_SYMBOL(phy_write_mmd);
 
 /**
- * __phy_modify() - Convenience function for modifying a PHY register
+ * __phy_modify_changed() - Convenience function for modifying a PHY register
  * @phydev: a pointer to a &struct phy_device
  * @regnum: register number
  * @mask: bit mask of bits to clear
@@ -539,16 +539,69 @@ EXPORT_SYMBOL(phy_write_mmd);
  *
  * Unlocked helper function which allows a PHY register to be modified as
  * new register value = (old register value & ~mask) | set
+ *
+ * Returns negative errno, 0 if there was no change, and 1 in case of change
  */
-int __phy_modify(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
+int __phy_modify_changed(struct phy_device *phydev, u32 regnum, u16 mask,
+			 u16 set)
 {
-	int ret;
+	int new, ret;
 
 	ret = __phy_read(phydev, regnum);
 	if (ret < 0)
 		return ret;
 
-	ret = __phy_write(phydev, regnum, (ret & ~mask) | set);
+	new = (ret & ~mask) | set;
+	if (new == ret)
+		return 0;
+
+	ret = __phy_write(phydev, regnum, new);
+
+	return ret < 0 ? ret : 1;
+}
+EXPORT_SYMBOL_GPL(__phy_modify_changed);
+
+/**
+ * phy_modify_changed - Function for modifying a PHY register
+ * @phydev: the phy_device struct
+ * @regnum: register number to modify
+ * @mask: bit mask of bits to clear
+ * @set: new value of bits set in mask to write to @regnum
+ *
+ * NOTE: MUST NOT be called from interrupt context,
+ * because the bus read/write functions may wait for an interrupt
+ * to conclude the operation.
+ *
+ * Returns negative errno, 0 if there was no change, and 1 in case of change
+ */
+int phy_modify_changed(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
+{
+	int ret;
+
+	mutex_lock(&phydev->mdio.bus->mdio_lock);
+	ret = __phy_modify_changed(phydev, regnum, mask, set);
+	mutex_unlock(&phydev->mdio.bus->mdio_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(phy_modify_changed);
+
+/**
+ * __phy_modify - Convenience function for modifying a PHY register
+ * @phydev: the phy_device struct
+ * @regnum: register number to modify
+ * @mask: bit mask of bits to clear
+ * @set: new value of bits set in mask to write to @regnum
+ *
+ * NOTE: MUST NOT be called from interrupt context,
+ * because the bus read/write functions may wait for an interrupt
+ * to conclude the operation.
+ */
+int __phy_modify(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
+{
+	int ret;
+
+	ret = __phy_modify_changed(phydev, regnum, mask, set);
 
 	return ret < 0 ? ret : 0;
 }
@@ -578,7 +631,7 @@ int phy_modify(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
 EXPORT_SYMBOL_GPL(phy_modify);
 
 /**
- * __phy_modify_mmd - Convenience function for modifying a register on MMD
+ * __phy_modify_mmd_changed - Function for modifying a register on MMD
  * @phydev: the phy_device struct
  * @devad: the MMD containing register to modify
  * @regnum: register number to modify
@@ -587,17 +640,73 @@ EXPORT_SYMBOL_GPL(phy_modify);
  *
  * Unlocked helper function which allows a MMD register to be modified as
  * new register value = (old register value & ~mask) | set
+ *
+ * Returns negative errno, 0 if there was no change, and 1 in case of change
  */
-int __phy_modify_mmd(struct phy_device *phydev, int devad, u32 regnum,
-		     u16 mask, u16 set)
+int __phy_modify_mmd_changed(struct phy_device *phydev, int devad, u32 regnum,
+			     u16 mask, u16 set)
 {
-	int ret;
+	int new, ret;
 
 	ret = __phy_read_mmd(phydev, devad, regnum);
 	if (ret < 0)
 		return ret;
 
-	ret = __phy_write_mmd(phydev, devad, regnum, (ret & ~mask) | set);
+	new = (ret & ~mask) | set;
+	if (new == ret)
+		return 0;
+
+	ret = __phy_write_mmd(phydev, devad, regnum, new);
+
+	return ret < 0 ? ret : 1;
+}
+EXPORT_SYMBOL_GPL(__phy_modify_mmd_changed);
+
+/**
+ * phy_modify_mmd_changed - Function for modifying a register on MMD
+ * @phydev: the phy_device struct
+ * @devad: the MMD containing register to modify
+ * @regnum: register number to modify
+ * @mask: bit mask of bits to clear
+ * @set: new value of bits set in mask to write to @regnum
+ *
+ * NOTE: MUST NOT be called from interrupt context,
+ * because the bus read/write functions may wait for an interrupt
+ * to conclude the operation.
+ *
+ * Returns negative errno, 0 if there was no change, and 1 in case of change
+ */
+int phy_modify_mmd_changed(struct phy_device *phydev, int devad, u32 regnum,
+			   u16 mask, u16 set)
+{
+	int ret;
+
+	mutex_lock(&phydev->mdio.bus->mdio_lock);
+	ret = __phy_modify_mmd_changed(phydev, devad, regnum, mask, set);
+	mutex_unlock(&phydev->mdio.bus->mdio_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(phy_modify_mmd_changed);
+
+/**
+ * __phy_modify_mmd - Convenience function for modifying a register on MMD
+ * @phydev: the phy_device struct
+ * @devad: the MMD containing register to modify
+ * @regnum: register number to modify
+ * @mask: bit mask of bits to clear
+ * @set: new value of bits set in mask to write to @regnum
+ *
+ * NOTE: MUST NOT be called from interrupt context,
+ * because the bus read/write functions may wait for an interrupt
+ * to conclude the operation.
+ */
+int __phy_modify_mmd(struct phy_device *phydev, int devad, u32 regnum,
+		     u16 mask, u16 set)
+{
+	int ret;
+
+	ret = __phy_modify_mmd_changed(phydev, devad, regnum, mask, set);
 
 	return ret < 0 ? ret : 0;
 }
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 8573d17ece0f..3d14e48aebc5 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -1516,7 +1516,7 @@ EXPORT_SYMBOL(phy_reset_after_clk_enable);
 static int genphy_config_advert(struct phy_device *phydev)
 {
 	u32 advertise;
-	int oldadv, adv, bmsr;
+	int bmsr, adv;
 	int err, changed = 0;
 
 	/* Only allow advertising what this PHY supports */
@@ -1529,22 +1529,14 @@ static int genphy_config_advert(struct phy_device *phydev)
 			    phydev->advertising);
 
 	/* Setup standard advertisement */
-	adv = phy_read(phydev, MII_ADVERTISE);
-	if (adv < 0)
-		return adv;
-
-	oldadv = adv;
-	adv &= ~(ADVERTISE_ALL | ADVERTISE_100BASE4 | ADVERTISE_PAUSE_CAP |
-		 ADVERTISE_PAUSE_ASYM);
-	adv |= ethtool_adv_to_mii_adv_t(advertise);
-
-	if (adv != oldadv) {
-		err = phy_write(phydev, MII_ADVERTISE, adv);
-
-		if (err < 0)
-			return err;
+	err = phy_modify_changed(phydev, MII_ADVERTISE,
+				 ADVERTISE_ALL | ADVERTISE_100BASE4 |
+				 ADVERTISE_PAUSE_CAP | ADVERTISE_PAUSE_ASYM,
+				 ethtool_adv_to_mii_adv_t(advertise));
+	if (err < 0)
+		return err;
+	if (err > 0)
 		changed = 1;
-	}
 
 	bmsr = phy_read(phydev, MII_BMSR);
 	if (bmsr < 0)
@@ -1558,25 +1550,20 @@ static int genphy_config_advert(struct phy_device *phydev)
 		return changed;
 
 	/* Configure gigabit if it's supported */
-	adv = phy_read(phydev, MII_CTRL1000);
-	if (adv < 0)
-		return adv;
-
-	oldadv = adv;
-	adv &= ~(ADVERTISE_1000FULL | ADVERTISE_1000HALF);
-
+	adv = 0;
 	if (linkmode_test_bit(ETHTOOL_LINK_MODE_1000baseT_Half_BIT,
 			      phydev->supported) ||
 	    linkmode_test_bit(ETHTOOL_LINK_MODE_1000baseT_Full_BIT,
 			      phydev->supported))
-		adv |= ethtool_adv_to_mii_ctrl1000_t(advertise);
+		adv = ethtool_adv_to_mii_ctrl1000_t(advertise);
 
-	if (adv != oldadv)
-		changed = 1;
-
-	err = phy_write(phydev, MII_CTRL1000, adv);
+	err = phy_modify_changed(phydev, MII_CTRL1000,
+				 ADVERTISE_1000FULL | ADVERTISE_1000HALF,
+				 adv);
 	if (err < 0)
 		return err;
+	if (err > 0)
+		changed = 1;
 
 	return changed;
 }
diff --git a/include/linux/phy.h b/include/linux/phy.h
index d2ffae992e4a..378da9a6165e 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -799,13 +799,21 @@ int phy_write_mmd(struct phy_device *phydev, int devad, u32 regnum, u16 val);
  */
 int __phy_write_mmd(struct phy_device *phydev, int devad, u32 regnum, u16 val);
 
+int __phy_modify_changed(struct phy_device *phydev, u32 regnum, u16 mask,
+			 u16 set);
+int phy_modify_changed(struct phy_device *phydev, u32 regnum, u16 mask,
+		       u16 set);
 int __phy_modify(struct phy_device *phydev, u32 regnum, u16 mask, u16 set);
 int phy_modify(struct phy_device *phydev, u32 regnum, u16 mask, u16 set);
 
+int __phy_modify_mmd_changed(struct phy_device *phydev, int devad, u32 regnum,
+			     u16 mask, u16 set);
+int phy_modify_mmd_changed(struct phy_device *phydev, int devad, u32 regnum,
+			   u16 mask, u16 set);
 int __phy_modify_mmd(struct phy_device *phydev, int devad, u32 regnum,
-		u16 mask, u16 set);
+		     u16 mask, u16 set);
 int phy_modify_mmd(struct phy_device *phydev, int devad, u32 regnum,
-		u16 mask, u16 set);
+		   u16 mask, u16 set);
 
 /**
  * __phy_set_bits - Convenience function for setting bits in a PHY register