net: fec: improve safety of suspend/resume/transmit timeout paths

We should hold the rtnl lock while suspending, resuming or processing
the transmit timeout to ensure that nothing will interfere while we
bring up, take down or restart the hardware.  The transmit timeout
could run if we're preempted during suspend.

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index f43c388e2eb93414fea632944e5e5190b9549aaa..1cd71a8d99967be9d20fe5f535959e46c6d3b620 100644 (file)
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -1068,8 +1068,10 @@ static void fec_enet_work(struct work_struct *work)
 
        if (fep->delay_work.timeout) {
                fep->delay_work.timeout = false;
+               rtnl_lock();
                fec_restart(fep->netdev, fep->full_duplex);
                netif_wake_queue(fep->netdev);
+               rtnl_unlock();
        }
 
        if (fep->delay_work.trig_tx) {
@@ -2680,11 +2682,14 @@ fec_suspend(struct device *dev)
        struct net_device *ndev = dev_get_drvdata(dev);
        struct fec_enet_private *fep = netdev_priv(ndev);
 
+       rtnl_lock();
        if (netif_running(ndev)) {
                phy_stop(fep->phy_dev);
                fec_stop(ndev);
                netif_device_detach(ndev);
        }
+       rtnl_unlock();
+
        fec_enet_clk_enable(ndev, false);
        pinctrl_pm_select_sleep_state(&fep->pdev->dev);
 
@@ -2712,11 +2717,13 @@ fec_resume(struct device *dev)
        if (ret)
                goto failed_clk;
 
+       rtnl_lock();
        if (netif_running(ndev)) {
                fec_restart(ndev, fep->full_duplex);
                netif_device_attach(ndev);
                phy_start(fep->phy_dev);
        }
+       rtnl_unlock();
 
        return 0;