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Commit c15e10e7 authored by Tim Beale's avatar Tim Beale Committed by David S. Miller
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net: phy: Make sure phy_start() always re-enables the phy interrupts 



This is an alternative way of fixing:
 commit db9683fb ("net: phy: Make sure PHY_RESUMING state change
                      is always processed")

When the PHY state transitions from PHY_HALTED to PHY_RESUMING, there are
two things we need to do:
1). Re-enable interrupts (and power up the physical link, if powered down)
2). Update the PHY state and net-device based on the link status.

There's no strict reason why #1 has to be done from within the main
phy_state_machine() function. There is a risk that other changes to the
PHY (e.g. setting speed/duplex, which calls phy_start_aneg()) could cause
a subsequent state transition before phy_state_machine() has processed
the PHY_RESUMING state change. This would leave the PHY with interrupts
disabled and/or still in the BMCR_PDOWN/low-power mode.

Moving enabling the interrupts and phy_resume() into phy_start() will
guarantee this work always gets done. As the PHY is already in the HALTED
state and interrupts are disabled, it shouldn't conflict with any work
being done in phy_state_machine(). The downside of this change is that if
the PHY_RESUMING state is ever entered from anywhere else, it'll also have
to repeat this work.

Signed-off-by: default avatarTim Beale <tim.beale@alliedtelesis.co.nz>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7764b9dd

drivers/net/phy/phy.c

+16 −13
Original line number Diff line number Diff line
@@ -465,7 +465,7 @@ int phy_start_aneg(struct phy_device *phydev) 
	if (err < 0)

		goto out_unlock;



	if (phydev->state != PHY_HALTED && phydev->state != PHY_RESUMING) {

	if (phydev->state != PHY_HALTED) {

		if (AUTONEG_ENABLE == phydev->autoneg) {

			phydev->state = PHY_AN;

			phydev->link_timeout = PHY_AN_TIMEOUT;
@@ -742,6 +742,9 @@ EXPORT_SYMBOL(phy_stop); 
 */

void phy_start(struct phy_device *phydev)

{

	bool do_resume = false;

	int err = 0;



	mutex_lock(&phydev->lock);



	switch (phydev->state) {
@@ -752,11 +755,22 @@ void phy_start(struct phy_device *phydev) 
		phydev->state = PHY_UP;

		break;

	case PHY_HALTED:

		/* make sure interrupts are re-enabled for the PHY */

		err = phy_enable_interrupts(phydev);

		if (err < 0)

			break;



		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);

}

EXPORT_SYMBOL(phy_start);
@@ -769,7 +783,7 @@ void phy_state_machine(struct work_struct *work) 
	struct delayed_work *dwork = to_delayed_work(work);

	struct phy_device *phydev =

			container_of(dwork, struct phy_device, state_queue);

	bool needs_aneg = false, do_suspend = false, do_resume = false;

	bool needs_aneg = false, do_suspend = false;

	int err = 0;



	mutex_lock(&phydev->lock);
@@ -888,14 +902,6 @@ void phy_state_machine(struct work_struct *work) 
		}

		break;

	case PHY_RESUMING:

		err = phy_clear_interrupt(phydev);

		if (err)

			break;



		err = phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED);

		if (err)

			break;



		if (AUTONEG_ENABLE == phydev->autoneg) {

			err = phy_aneg_done(phydev);

			if (err < 0)
@@ -933,7 +939,6 @@ void phy_state_machine(struct work_struct *work) 
			}

			phydev->adjust_link(phydev->attached_dev);

		}

		do_resume = true;

		break;

	}
@@ -943,8 +948,6 @@ void phy_state_machine(struct work_struct *work) 
		err = phy_start_aneg(phydev);

	else if (do_suspend)

		phy_suspend(phydev);

	else if (do_resume)

		phy_resume(phydev);



	if (err < 0)

		phy_error(phydev);