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Commit eab12771 authored by Florian Fainelli's avatar Florian Fainelli Committed by David S. Miller
Browse files

net: phy: Avoid deadlock during phy_error() 



phy_error() is called in the PHY state machine workqueue context, and
calls phy_trigger_machine() which does a cancel_delayed_work_sync() of
the workqueue we execute from, causing a deadlock situation.

Augment phy_trigger_machine() machine with a sync boolean indicating
whether we should use cancel_*_sync() or just cancel_*_work().

Fixes: 3c293f4e ("net: phy: Trigger state machine on state change and not polling.")
Reported-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 9f427a0e

drivers/net/phy/phy.c

+9 −5
Original line number Diff line number Diff line
@@ -649,14 +649,18 @@ void phy_start_machine(struct phy_device *phydev) 
 * phy_trigger_machine - trigger the state machine to run

 *

 * @phydev: the phy_device struct

 * @sync: indicate whether we should wait for the workqueue cancelation

 *

 * Description: There has been a change in state which requires that the

 *   state machine runs.

 */



static void phy_trigger_machine(struct phy_device *phydev)

static void phy_trigger_machine(struct phy_device *phydev, bool sync)

{

	if (sync)

		cancel_delayed_work_sync(&phydev->state_queue);

	else

		cancel_delayed_work(&phydev->state_queue);

	queue_delayed_work(system_power_efficient_wq, &phydev->state_queue, 0);

}
@@ -693,7 +697,7 @@ static void phy_error(struct phy_device *phydev) 
	phydev->state = PHY_HALTED;

	mutex_unlock(&phydev->lock);



	phy_trigger_machine(phydev);

	phy_trigger_machine(phydev, false);

}



/**
@@ -840,7 +844,7 @@ void phy_change(struct phy_device *phydev) 
	}



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

	phy_trigger_machine(phydev);

	phy_trigger_machine(phydev, true);

	return;



ignore:
@@ -942,7 +946,7 @@ void phy_start(struct phy_device *phydev) 
	if (do_resume)

		phy_resume(phydev);



	phy_trigger_machine(phydev);

	phy_trigger_machine(phydev, true);

}

EXPORT_SYMBOL(phy_start);