Hi Marc, Sean Nyekjaer reported the issue, but the fix is incorrect. https://www.spinics.net/lists/linux-can/msg01447.html Could you help to add Sean Nyekjaer to this thread as I can't get the email address. You can add the "Reported-by" tag if you pick up the patch. Thanks a lot! Best Regards, Joakim Zhang > -----Original Message----- > From: Joakim Zhang > Sent: 2019年5月17日 10:39 > To: mkl@xxxxxxxxxxxxxx; linux-can@xxxxxxxxxxxxxxx > Cc: dl-linux-imx <linux-imx@xxxxxxx>; wg@xxxxxxxxxxxxxx; > netdev@xxxxxxxxxxxxxxx; Joakim Zhang <qiangqing.zhang@xxxxxxx> > Subject: [PATCH] can: flexcan: fix deadlock when using self wakeup > > As reproted by Sean Nyekjaer bellow: > When suspending, when there is still can traffic on the interfaces the flexcan > immediately wakes the platform again. > As it should :-) > But it throws this error msg: > [ 3169.378661] PM: noirq suspend of devices failed > > On the way down to suspend the interface that throws the error message does > call flexcan_suspend but fails to call flexcan_noirq_suspend. > That means the flexcan_enter_stop_mode is called, but on the way out of > suspend the driver only calls flexcan_resume and skips flexcan_noirq_resume, > thus it doesn't call flexcan_exit_stop_mode. > This leaves the flexcan in stop mode, and with the current driver it can't > recover from this even with a soft reboot, it requires a hard reboot. > > Fixes: de3578c198c6 ("can: flexcan: add self wakeup support") > > This patch intends to fix the issue, and also add comment to explain the > wakeup flow. > > Signed-off-by: Joakim Zhang <qiangqing.zhang@xxxxxxx> > --- > drivers/net/can/flexcan.c | 17 +++++++++++++++++ > 1 file changed, 17 insertions(+) > > diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c index > e35083ff31ee..6fbce473a8c7 100644 > --- a/drivers/net/can/flexcan.c > +++ b/drivers/net/can/flexcan.c > @@ -286,6 +286,7 @@ struct flexcan_priv { > const struct flexcan_devtype_data *devtype_data; > struct regulator *reg_xceiver; > struct flexcan_stop_mode stm; > + bool in_stop_mode; > > /* Read and Write APIs */ > u32 (*read)(void __iomem *addr); > @@ -1653,6 +1654,7 @@ static int __maybe_unused flexcan_suspend(struct > device *device) > if (device_may_wakeup(device)) { > enable_irq_wake(dev->irq); > flexcan_enter_stop_mode(priv); > + priv->in_stop_mode = true; > } else { > err = flexcan_chip_disable(priv); > if (err) > @@ -1679,6 +1681,11 @@ static int __maybe_unused flexcan_resume(struct > device *device) > netif_device_attach(dev); > netif_start_queue(dev); > if (device_may_wakeup(device)) { > + if (priv->in_stop_mode) { > + flexcan_enable_wakeup_irq(priv, false); > + flexcan_exit_stop_mode(priv); > + priv->in_stop_mode = false; > + } > disable_irq_wake(dev->irq); > } else { > err = pm_runtime_force_resume(device); @@ -1715,6 > +1722,11 @@ static int __maybe_unused flexcan_noirq_suspend(struct device > *device) > struct net_device *dev = dev_get_drvdata(device); > struct flexcan_priv *priv = netdev_priv(dev); > > + /* Need enable wakeup interrupt in noirq suspend stage. Otherwise, > + * it will trigger continuously wakeup interrupt if the wakeup event > + * comes before noirq suspend stage, and simultaneously in has enter > + * the stop mode. > + */ > if (netif_running(dev) && device_may_wakeup(device)) > flexcan_enable_wakeup_irq(priv, true); > > @@ -1726,9 +1738,14 @@ static int __maybe_unused > flexcan_noirq_resume(struct device *device) > struct net_device *dev = dev_get_drvdata(device); > struct flexcan_priv *priv = netdev_priv(dev); > > + /* Need exit stop mode in noirq resume stage. Otherwise, it will > + * trigger continuously wakeup interrupt if the wakeup event comes, > + * and simultaneously it has still in stop mode. > + */ > if (netif_running(dev) && device_may_wakeup(device)) { > flexcan_enable_wakeup_irq(priv, false); > flexcan_exit_stop_mode(priv); > + priv->in_stop_mode = false; > } > > return 0; > -- > 2.17.1
