From 0b6f65c707e5ec5e33916820e2a4a628e2b4576c Mon Sep 17 00:00:00 2001 From: Joakim Zhang Date: Tue, 14 Dec 2021 18:50:46 +0800 Subject: [PATCH] net: fec: fix system hang during suspend/resume 1. During normal suspend (WoL not enabled) process, system has posibility to hang. The root cause is TXF interrupt coming after clocks disabled, system hang when accessing registers from interrupt handler. To fix this issue, disable all interrupts when system suspend. 2. System also has posibility to hang with WoL enabled during suspend, after entering stop mode, then magic pattern coming after clocks disabled, system will be waked up, and interrupt handler will be called, system hang when access registers. To fix this issue, disable wakeup irq in .suspend(), and enable it in .resume(). Signed-off-by: Joakim Zhang Signed-off-by: David S. Miller --- drivers/net/ethernet/freescale/fec_main.c | 46 +++++++++++++++++------ 1 file changed, 34 insertions(+), 12 deletions(-) diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c index 613b8180a1bd..796133de527e 100644 --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -1185,6 +1185,21 @@ static void fec_enet_stop_mode(struct fec_enet_private *fep, bool enabled) } } +static void fec_irqs_disable(struct net_device *ndev) +{ + struct fec_enet_private *fep = netdev_priv(ndev); + + writel(0, fep->hwp + FEC_IMASK); +} + +static void fec_irqs_disable_except_wakeup(struct net_device *ndev) +{ + struct fec_enet_private *fep = netdev_priv(ndev); + + writel(0, fep->hwp + FEC_IMASK); + writel(FEC_ENET_WAKEUP, fep->hwp + FEC_IMASK); +} + static void fec_stop(struct net_device *ndev) { @@ -1211,15 +1226,13 @@ fec_stop(struct net_device *ndev) writel(1, fep->hwp + FEC_ECNTRL); udelay(10); } - writel(FEC_DEFAULT_IMASK, fep->hwp + FEC_IMASK); } else { - writel(FEC_DEFAULT_IMASK | FEC_ENET_WAKEUP, fep->hwp + FEC_IMASK); val = readl(fep->hwp + FEC_ECNTRL); val |= (FEC_ECR_MAGICEN | FEC_ECR_SLEEP); writel(val, fep->hwp + FEC_ECNTRL); - fec_enet_stop_mode(fep, true); } writel(fep->phy_speed, fep->hwp + FEC_MII_SPEED); + writel(FEC_DEFAULT_IMASK, fep->hwp + FEC_IMASK); /* We have to keep ENET enabled to have MII interrupt stay working */ if (fep->quirks & FEC_QUIRK_ENET_MAC && @@ -2877,15 +2890,10 @@ fec_enet_set_wol(struct net_device *ndev, struct ethtool_wolinfo *wol) return -EINVAL; device_set_wakeup_enable(&ndev->dev, wol->wolopts & WAKE_MAGIC); - if (device_may_wakeup(&ndev->dev)) { + if (device_may_wakeup(&ndev->dev)) fep->wol_flag |= FEC_WOL_FLAG_ENABLE; - if (fep->wake_irq > 0) - enable_irq_wake(fep->wake_irq); - } else { + else fep->wol_flag &= (~FEC_WOL_FLAG_ENABLE); - if (fep->wake_irq > 0) - disable_irq_wake(fep->wake_irq); - } return 0; } @@ -4057,9 +4065,19 @@ static int __maybe_unused fec_suspend(struct device *dev) netif_device_detach(ndev); netif_tx_unlock_bh(ndev); fec_stop(ndev); - fec_enet_clk_enable(ndev, false); - if (!(fep->wol_flag & FEC_WOL_FLAG_ENABLE)) + if (!(fep->wol_flag & FEC_WOL_FLAG_ENABLE)) { + fec_irqs_disable(ndev); pinctrl_pm_select_sleep_state(&fep->pdev->dev); + } else { + fec_irqs_disable_except_wakeup(ndev); + if (fep->wake_irq > 0) { + disable_irq(fep->wake_irq); + enable_irq_wake(fep->wake_irq); + } + fec_enet_stop_mode(fep, true); + } + /* It's safe to disable clocks since interrupts are masked */ + fec_enet_clk_enable(ndev, false); } rtnl_unlock(); @@ -4097,6 +4115,10 @@ static int __maybe_unused fec_resume(struct device *dev) } if (fep->wol_flag & FEC_WOL_FLAG_ENABLE) { fec_enet_stop_mode(fep, false); + if (fep->wake_irq) { + disable_irq_wake(fep->wake_irq); + enable_irq(fep->wake_irq); + } val = readl(fep->hwp + FEC_ECNTRL); val &= ~(FEC_ECR_MAGICEN | FEC_ECR_SLEEP); -- 2.25.1