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Commit 2274d77c authored by Brad Mouring's avatar Brad Mouring Committed by Greg Kroah-Hartman
Browse files

net: phy: Tell caller result of phy_change() 




[ Upstream commit a2c054a896b8ac794ddcfc7c92e2dc7ec4ed4ed5 ]

In 664fcf12 (net: phy: Threaded interrupts allow some simplification)
the phy_interrupt system was changed to use a traditional threaded
interrupt scheme instead of a workqueue approach.

With this change, the phy status check moved into phy_change, which
did not report back to the caller whether or not the interrupt was
handled. This means that, in the case of a shared phy interrupt,
only the first phydev's interrupt registers are checked (since
phy_interrupt() would always return IRQ_HANDLED). This leads to
interrupt storms when it is a secondary device that's actually the
interrupt source.

Signed-off-by: default avatarBrad Mouring <brad.mouring@ni.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 42cf2a1e

drivers/net/phy/phy.c

+86 −87
Original line number Diff line number Diff line
@@ -614,6 +614,91 @@ static void phy_error(struct phy_device *phydev) 
	phy_trigger_machine(phydev, false);

}



/**

 * phy_disable_interrupts - Disable the PHY interrupts from the PHY side

 * @phydev: target phy_device struct

 */

static int phy_disable_interrupts(struct phy_device *phydev)

{

	int err;



	/* Disable PHY interrupts */

	err = phy_config_interrupt(phydev, PHY_INTERRUPT_DISABLED);

	if (err)

		goto phy_err;



	/* Clear the interrupt */

	err = phy_clear_interrupt(phydev);

	if (err)

		goto phy_err;



	return 0;



phy_err:

	phy_error(phydev);



	return err;

}



/**

 * phy_change - Called by the phy_interrupt to handle PHY changes

 * @phydev: phy_device struct that interrupted

 */

static irqreturn_t phy_change(struct phy_device *phydev)

{

	if (phy_interrupt_is_valid(phydev)) {

		if (phydev->drv->did_interrupt &&

		    !phydev->drv->did_interrupt(phydev))

			goto ignore;



		if (phy_disable_interrupts(phydev))

			goto phy_err;

	}



	mutex_lock(&phydev->lock);

	if ((PHY_RUNNING == phydev->state) || (PHY_NOLINK == phydev->state))

		phydev->state = PHY_CHANGELINK;

	mutex_unlock(&phydev->lock);



	if (phy_interrupt_is_valid(phydev)) {

		atomic_dec(&phydev->irq_disable);

		enable_irq(phydev->irq);



		/* Reenable interrupts */

		if (PHY_HALTED != phydev->state &&

		    phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED))

			goto irq_enable_err;

	}



	/* reschedule state queue work to run as soon as possible */

	phy_trigger_machine(phydev, true);

	return IRQ_HANDLED;



ignore:

	atomic_dec(&phydev->irq_disable);

	enable_irq(phydev->irq);

	return IRQ_NONE;



irq_enable_err:

	disable_irq(phydev->irq);

	atomic_inc(&phydev->irq_disable);

phy_err:

	phy_error(phydev);

	return IRQ_NONE;

}



/**

 * phy_change_work - Scheduled by the phy_mac_interrupt to handle PHY changes

 * @work: work_struct that describes the work to be done

 */

void phy_change_work(struct work_struct *work)

{

	struct phy_device *phydev =

		container_of(work, struct phy_device, phy_queue);



	phy_change(phydev);

}



/**

 * phy_interrupt - PHY interrupt handler

 * @irq: interrupt line
@@ -632,9 +717,7 @@ static irqreturn_t phy_interrupt(int irq, void *phy_dat) 
	disable_irq_nosync(irq);

	atomic_inc(&phydev->irq_disable);



	phy_change(phydev);



	return IRQ_HANDLED;

	return phy_change(phydev);

}



/**
@@ -651,32 +734,6 @@ static int phy_enable_interrupts(struct phy_device *phydev) 
	return phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED);

}



/**

 * phy_disable_interrupts - Disable the PHY interrupts from the PHY side

 * @phydev: target phy_device struct

 */

static int phy_disable_interrupts(struct phy_device *phydev)

{

	int err;



	/* Disable PHY interrupts */

	err = phy_config_interrupt(phydev, PHY_INTERRUPT_DISABLED);

	if (err)

		goto phy_err;



	/* Clear the interrupt */

	err = phy_clear_interrupt(phydev);

	if (err)

		goto phy_err;



	return 0;



phy_err:

	phy_error(phydev);



	return err;

}



/**

 * phy_start_interrupts - request and enable interrupts for a PHY device

 * @phydev: target phy_device struct
@@ -727,64 +784,6 @@ int phy_stop_interrupts(struct phy_device *phydev) 
}

EXPORT_SYMBOL(phy_stop_interrupts);



/**

 * phy_change - Called by the phy_interrupt to handle PHY changes

 * @phydev: phy_device struct that interrupted

 */

void phy_change(struct phy_device *phydev)

{

	if (phy_interrupt_is_valid(phydev)) {

		if (phydev->drv->did_interrupt &&

		    !phydev->drv->did_interrupt(phydev))

			goto ignore;



		if (phy_disable_interrupts(phydev))

			goto phy_err;

	}



	mutex_lock(&phydev->lock);

	if ((PHY_RUNNING == phydev->state) || (PHY_NOLINK == phydev->state))

		phydev->state = PHY_CHANGELINK;

	mutex_unlock(&phydev->lock);



	if (phy_interrupt_is_valid(phydev)) {

		atomic_dec(&phydev->irq_disable);

		enable_irq(phydev->irq);



		/* Reenable interrupts */

		if (PHY_HALTED != phydev->state &&

		    phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED))

			goto irq_enable_err;

	}



	/* reschedule state queue work to run as soon as possible */

	phy_trigger_machine(phydev, true);

	return;



ignore:

	atomic_dec(&phydev->irq_disable);

	enable_irq(phydev->irq);

	return;



irq_enable_err:

	disable_irq(phydev->irq);

	atomic_inc(&phydev->irq_disable);

phy_err:

	phy_error(phydev);

}



/**

 * phy_change_work - Scheduled by the phy_mac_interrupt to handle PHY changes

 * @work: work_struct that describes the work to be done

 */

void phy_change_work(struct work_struct *work)

{

	struct phy_device *phydev =

		container_of(work, struct phy_device, phy_queue);



	phy_change(phydev);

}



/**

 * phy_stop - Bring down the PHY link, and stop checking the status

 * @phydev: target phy_device struct

include/linux/phy.h

+0 −1
Original line number Diff line number Diff line
@@ -895,7 +895,6 @@ int phy_driver_register(struct phy_driver *new_driver, struct module *owner); 
int phy_drivers_register(struct phy_driver *new_driver, int n,

			 struct module *owner);

void phy_state_machine(struct work_struct *work);

void phy_change(struct phy_device *phydev);

void phy_change_work(struct work_struct *work);

void phy_mac_interrupt(struct phy_device *phydev, int new_link);

void phy_start_machine(struct phy_device *phydev);