From feaa5bab43350b95428dc01cf1f064305e72dd87 Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Fri, 20 Jan 2017 15:31:52 -0800 Subject: [PATCH] net: phy: Avoid deadlock during phy_error() [ Upstream commit eab127717a6af54401ba534790c793ec143cd1fc ] 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: 3c293f4e08b5 ("net: phy: Trigger state machine on state change and not polling.") Reported-by: Russell King Signed-off-by: Florian Fainelli Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/phy/phy.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c index f424b86..201ffa5 100644 --- a/drivers/net/phy/phy.c +++ b/drivers/net/phy/phy.c @@ -611,14 +611,18 @@ 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) { - cancel_delayed_work_sync(&phydev->state_queue); + 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); } @@ -655,7 +659,7 @@ 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); } /** @@ -817,7 +821,7 @@ void phy_change(struct work_struct *work) } /* reschedule state queue work to run as soon as possible */ - phy_trigger_machine(phydev); + phy_trigger_machine(phydev, true); return; ignore: @@ -907,7 +911,7 @@ 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); -- 2.7.4