From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Fainelli Subject: [PATCH net] net: phy: Avoid deadlock during phy_error() Date: Fri, 20 Jan 2017 15:31:52 -0800 Message-ID: <20170120233152.16244-1-f.fainelli@gmail.com> Cc: davem@davemloft.net, andrew@lunn.ch, kyle.roeschley@ni.com, rmk+kernel@armlinux.org.uk, Florian Fainelli To: netdev@vger.kernel.org Return-path: Received: from mail-pg0-f67.google.com ([74.125.83.67]:35984 "EHLO mail-pg0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752474AbdATXcA (ORCPT ); Fri, 20 Jan 2017 18:32:00 -0500 Received: by mail-pg0-f67.google.com with SMTP id 75so7913054pgf.3 for ; Fri, 20 Jan 2017 15:32:00 -0800 (PST) Sender: netdev-owner@vger.kernel.org List-ID: 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 --- 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 48da6e93c3f7..e687a9cb4a37 100644 --- a/drivers/net/phy/phy.c +++ b/drivers/net/phy/phy.c @@ -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) { - 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 @@ 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); -- 2.11.0