diff --git a/drivers/net/phy/at803x.c b/drivers/net/phy/at803x.c
index 4c75cfcdeaec..a20d1f5e4dbf 100644
--- a/drivers/net/phy/at803x.c
+++ b/drivers/net/phy/at803x.c
@@ -258,38 +258,22 @@ static int at803x_suspend(struct phy_device *phydev)
 	int value;
 	int wol_enabled;
 
-	mutex_lock(&phydev->lock);
-
 	value = phy_read(phydev, AT803X_INTR_ENABLE);
 	wol_enabled = value & AT803X_INTR_ENABLE_WOL;
 
-	value = phy_read(phydev, MII_BMCR);
-
 	if (wol_enabled)
-		value |= BMCR_ISOLATE;
+		value = BMCR_ISOLATE;
 	else
-		value |= BMCR_PDOWN;
-
-	phy_write(phydev, MII_BMCR, value);
+		value = BMCR_PDOWN;
 
-	mutex_unlock(&phydev->lock);
+	phy_modify(phydev, MII_BMCR, value, value);
 
 	return 0;
 }
 
 static int at803x_resume(struct phy_device *phydev)
 {
-	int value;
-
-	mutex_lock(&phydev->lock);
-
-	value = phy_read(phydev, MII_BMCR);
-	value &= ~(BMCR_PDOWN | BMCR_ISOLATE);
-	phy_write(phydev, MII_BMCR, value);
-
-	mutex_unlock(&phydev->lock);
-
-	return 0;
+	return phy_modify(phydev, MII_BMCR, BMCR_PDOWN | BMCR_ISOLATE, 0);
 }
 
 static int at803x_probe(struct phy_device *phydev)
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 1bf3adcdcbac..d5adb00eafdf 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -651,6 +651,38 @@ int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
 EXPORT_SYMBOL(mdiobus_write);
 
 /**
+ * mdiobus_modify - Convenience function for writing a given MII mgmt register
+ * @bus: the mii_bus struct
+ * @addr: the phy address
+ * @regnum: register number to write
+ * @mask: bits to mask off from the register @regnum
+ * @val: 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 mdiobus_modify(struct mii_bus *bus, int addr, u32 regnum, u16 mask, u16 val)
+{
+	int retval;
+	int err;
+
+	BUG_ON(in_interrupt());
+
+	mutex_lock(&bus->mdio_lock);
+	err = retval = __mdiobus_read(bus, addr, regnum);
+	if (err >= 0) {
+		retval &= ~mask;
+		retval |= val & mask;
+		err = __mdiobus_write(bus, addr, regnum, retval);
+	}
+	mutex_unlock(&bus->mdio_lock);
+
+	return err;
+}
+EXPORT_SYMBOL(mdiobus_modify);
+
+/**
  * mdio_bus_match - determine if given MDIO driver supports the given
  *		    MDIO device
  * @dev: target MDIO device
diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index fdb43dd9b5cd..9e9438caa2b7 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -711,22 +711,9 @@ static int kszphy_suspend(struct phy_device *phydev)
 
 static int kszphy_resume(struct phy_device *phydev)
 {
-	int ret;
-
 	genphy_resume(phydev);
 
-	ret = kszphy_config_reset(phydev);
-	if (ret)
-		return ret;
-
-	/* Enable PHY Interrupts */
-	if (phy_interrupt_is_valid(phydev)) {
-		phydev->interrupts = PHY_INTERRUPT_ENABLED;
-		if (phydev->drv->config_intr)
-			phydev->drv->config_intr(phydev);
-	}
-
-	return 0;
+	return kszphy_config_reset(phydev);
 }
 
 static int kszphy_probe(struct phy_device *phydev)
diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index f2a83ab00e71..874740957606 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -844,7 +844,6 @@ EXPORT_SYMBOL(phy_stop);
  */
 void phy_start(struct phy_device *phydev)
 {
-	bool do_resume = false;
 	int err = 0;
 
 	mutex_lock(&phydev->lock);
@@ -857,6 +856,9 @@ void phy_start(struct phy_device *phydev)
 		phydev->state = PHY_UP;
 		break;
 	case PHY_HALTED:
+		/* if phy was suspended, bring the physical link up again */
+		phy_resume(phydev);
+
 		/* make sure interrupts are re-enabled for the PHY */
 		if (phydev->irq != PHY_POLL) {
 			err = phy_enable_interrupts(phydev);
@@ -865,17 +867,12 @@ void phy_start(struct phy_device *phydev)
 		}
 
 		phydev->state = PHY_RESUMING;
-		do_resume = true;
 		break;
 	default:
 		break;
 	}
 	mutex_unlock(&phydev->lock);
 
-	/* if phy was suspended, bring the physical link up again */
-	if (do_resume)
-		phy_resume(phydev);
-
 	phy_trigger_machine(phydev, true);
 }
 EXPORT_SYMBOL(phy_start);
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 67f25ac29025..d0d98e6f6406 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -135,7 +135,9 @@ static int mdio_bus_phy_resume(struct device *dev)
 	if (!mdio_bus_phy_may_suspend(phydev))
 		goto no_resume;
 
+	mutex_lock(&phydev->lock);
 	ret = phy_resume(phydev);
+	mutex_unlock(&phydev->lock);
 	if (ret < 0)
 		return ret;
 
@@ -1026,7 +1028,9 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev,
 	if (err)
 		goto error;
 
+	mutex_lock(&phydev->lock);
 	phy_resume(phydev);
+	mutex_unlock(&phydev->lock);
 	phy_led_triggers_register(phydev);
 
 	return err;
@@ -1157,6 +1161,8 @@ int phy_resume(struct phy_device *phydev)
 	struct phy_driver *phydrv = to_phy_driver(phydev->mdio.dev.driver);
 	int ret = 0;
 
+	WARN_ON(!mutex_is_locked(&phydev->lock));
+
 	if (phydev->drv && phydrv->resume)
 		ret = phydrv->resume(phydev);
 
@@ -1322,9 +1328,8 @@ static int genphy_config_eee_advert(struct phy_device *phydev)
  */
 int genphy_setup_forced(struct phy_device *phydev)
 {
-	int ctl = phy_read(phydev, MII_BMCR);
+	u16 ctl = 0;
 
-	ctl &= BMCR_LOOPBACK | BMCR_ISOLATE | BMCR_PDOWN;
 	phydev->pause = 0;
 	phydev->asym_pause = 0;
 
@@ -1336,7 +1341,10 @@ int genphy_setup_forced(struct phy_device *phydev)
 	if (DUPLEX_FULL == phydev->duplex)
 		ctl |= BMCR_FULLDPLX;
 
-	return phy_write(phydev, MII_BMCR, ctl);
+	return phy_modify(phydev, MII_BMCR,
+			  BMCR_LOOPBACK | BMCR_ISOLATE | BMCR_PDOWN |
+			  BMCR_SPEED1000 | BMCR_SPEED100 | BMCR_FULLDPLX,
+			  ctl);
 }
 EXPORT_SYMBOL(genphy_setup_forced);
 
@@ -1346,17 +1354,10 @@ EXPORT_SYMBOL(genphy_setup_forced);
  */
 int genphy_restart_aneg(struct phy_device *phydev)
 {
-	int ctl = phy_read(phydev, MII_BMCR);
-
-	if (ctl < 0)
-		return ctl;
-
-	ctl |= BMCR_ANENABLE | BMCR_ANRESTART;
-
 	/* Don't isolate the PHY if we're negotiating */
-	ctl &= ~BMCR_ISOLATE;
-
-	return phy_write(phydev, MII_BMCR, ctl);
+	return phy_modify(phydev, MII_BMCR,
+			  BMCR_ANENABLE | BMCR_ANRESTART | BMCR_ISOLATE,
+			  BMCR_ANENABLE | BMCR_ANRESTART);
 }
 EXPORT_SYMBOL(genphy_restart_aneg);
 
@@ -1622,48 +1623,20 @@ EXPORT_SYMBOL(genphy_config_init);
 
 int genphy_suspend(struct phy_device *phydev)
 {
-	int value;
-
-	mutex_lock(&phydev->lock);
-
-	value = phy_read(phydev, MII_BMCR);
-	phy_write(phydev, MII_BMCR, value | BMCR_PDOWN);
-
-	mutex_unlock(&phydev->lock);
-
-	return 0;
+	return phy_modify(phydev, MII_BMCR, BMCR_PDOWN, BMCR_PDOWN);
 }
 EXPORT_SYMBOL(genphy_suspend);
 
 int genphy_resume(struct phy_device *phydev)
 {
-	int value;
-
-	mutex_lock(&phydev->lock);
-
-	value = phy_read(phydev, MII_BMCR);
-	phy_write(phydev, MII_BMCR, value & ~BMCR_PDOWN);
-
-	mutex_unlock(&phydev->lock);
-
-	return 0;
+	return phy_modify(phydev, MII_BMCR, BMCR_PDOWN, 0);
 }
 EXPORT_SYMBOL(genphy_resume);
 
 int genphy_loopback(struct phy_device *phydev, bool enable)
 {
-	int value;
-
-	value = phy_read(phydev, MII_BMCR);
-	if (value < 0)
-		return value;
-
-	if (enable)
-		value |= BMCR_LOOPBACK;
-	else
-		value &= ~BMCR_LOOPBACK;
-
-	return phy_write(phydev, MII_BMCR, value);
+	return phy_modify(phydev, MII_BMCR, BMCR_LOOPBACK,
+			  enable ? BMCR_LOOPBACK : 0);
 }
 EXPORT_SYMBOL(genphy_loopback);
 
diff --git a/include/linux/mdio.h b/include/linux/mdio.h
index 4be30adc033b..8e69211685be 100644
--- a/include/linux/mdio.h
+++ b/include/linux/mdio.h
@@ -264,6 +264,7 @@ int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum);
 int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum);
 int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val);
 int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val);
+int mdiobus_modify(struct mii_bus *bus, int addr, u32 regnum, u16 mask, u16 val);
 
 int mdiobus_register_device(struct mdio_device *mdiodev);
 int mdiobus_unregister_device(struct mdio_device *mdiodev);
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 03a259f128f9..afe5d963a98c 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -766,6 +766,24 @@ static inline int __phy_write(struct phy_device *phydev, u32 regnum, u16 val)
 }
 
 /**
+ * phy_modify - Convenience function for modifying a given PHY register
+ * @phydev: the phy_device struct
+ * @regnum: register number to write
+ * @mask: bits to mask off from the register @regnum
+ * @val: 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.
+ */
+static inline int phy_modify(struct phy_device *phydev, u32 regnum, u16 mask,
+			     u16 val)
+{
+	return mdiobus_modify(phydev->mdio.bus, phydev->mdio.addr, regnum,
+			      mask, val);
+}
+
+/**
  * phy_interrupt_is_valid - Convenience function for testing a given PHY irq
  * @phydev: the phy_device struct
  *
