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: 3c293f4e08b5 ("net: phy: Trigger state machine on state change and not polling.")
Reported-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index 48da6e9..e687a9c 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -649,14 +649,18 @@
* 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);
}
@@ -693,7 +697,7 @@
phydev->state = PHY_HALTED;
mutex_unlock(&phydev->lock);
- phy_trigger_machine(phydev);
+ phy_trigger_machine(phydev, false);
}
/**
@@ -840,7 +844,7 @@
}
/* 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 @@
if (do_resume)
phy_resume(phydev);
- phy_trigger_machine(phydev);
+ phy_trigger_machine(phydev, true);
}
EXPORT_SYMBOL(phy_start);