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Commit f5e64032 authored by Russell King's avatar Russell King Committed by David S. Miller
Browse files

net: phy: fix resume handling 



When a PHY has the BMCR_PDOWN bit set, it may decide to ignore writes
to other registers, or reset the registers to power-on defaults.
Micrel PHYs do this for their interrupt registers.

The current structure of phylib tries to enable interrupts before
resuming (and releasing) the BMCR_PDOWN bit.  This fails, causing
Micrel PHYs to stop working after a suspend/resume sequence if they
are using interrupts.

Fix this by ensuring that the PHY driver resume methods do not take
the phydev->lock mutex themselves, but the callers of phy_resume()
take that lock.  This then allows us to move the call to phy_resume()
before we enable interrupts in phy_start().

Signed-off-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent cd8165c3

drivers/net/phy/at803x.c

+0 −4
Original line number Diff line number Diff line
@@ -239,14 +239,10 @@ 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;

}

drivers/net/phy/phy.c

+3 −6
Original line number Diff line number Diff line
@@ -828,7 +828,6 @@ EXPORT_SYMBOL(phy_stop); 
 */

void phy_start(struct phy_device *phydev)

{

	bool do_resume = false;

	int err = 0;



	mutex_lock(&phydev->lock);
@@ -841,6 +840,9 @@ 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);
@@ -849,17 +851,12 @@ 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);

drivers/net/phy/phy_device.c

+6 −4
Original line number Diff line number Diff line
@@ -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);
@@ -1639,13 +1645,9 @@ 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;

}

EXPORT_SYMBOL(genphy_resume);