From 0b2991a8ed32b5d9ba0a7c3441a72e1c1a1c4fde Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Sat, 14 Jan 2017 22:29:05 +0100 Subject: [PATCH] kernel: make ledtrig-netdev use a work queue for updates This fixes hangs in igb that happen if the update call interrupts an already existing dev_get_stats call. In that case the calling CPU deadlocks because it's trying to acquire the same spinlock recursively. Signed-off-by: Felix Fietkau --- .../files/drivers/leds/ledtrig-netdev.c | 32 +++++++++---------- 1 file changed, 16 insertions(+), 16 deletions(-) diff --git a/target/linux/generic/files/drivers/leds/ledtrig-netdev.c b/target/linux/generic/files/drivers/leds/ledtrig-netdev.c index cfa4dc0758..2181a26250 100644 --- a/target/linux/generic/files/drivers/leds/ledtrig-netdev.c +++ b/target/linux/generic/files/drivers/leds/ledtrig-netdev.c @@ -70,7 +70,7 @@ struct led_netdev_data { spinlock_t lock; - struct timer_list timer; + struct delayed_work work; struct notifier_block notifier; struct led_classdev *led_cdev; @@ -91,7 +91,7 @@ static void set_baseline_state(struct led_netdev_data *trigger_data) led_set_brightness(trigger_data->led_cdev, LED_OFF); if ((trigger_data->mode & (MODE_TX | MODE_RX)) != 0 && trigger_data->link_up) - mod_timer(&trigger_data->timer, jiffies + trigger_data->interval); + schedule_delayed_work(&trigger_data->work, trigger_data->interval); } static ssize_t led_device_name_show(struct device *dev, @@ -116,8 +116,9 @@ static ssize_t led_device_name_store(struct device *dev, if (size < 0 || size >= IFNAMSIZ) return -EINVAL; + cancel_delayed_work_sync(&trigger_data->work); + spin_lock_bh(&trigger_data->lock); - del_timer_sync(&trigger_data->timer); strcpy(trigger_data->device_name, buf); if (size > 0 && trigger_data->device_name[size-1] == '\n') @@ -201,11 +202,10 @@ static ssize_t led_mode_store(struct device *dev, if (new_mode == -1) return -EINVAL; - spin_lock_bh(&trigger_data->lock); - del_timer_sync(&trigger_data->timer); + cancel_delayed_work_sync(&trigger_data->work); + spin_lock_bh(&trigger_data->lock); trigger_data->mode = new_mode; - set_baseline_state(trigger_data); spin_unlock_bh(&trigger_data->lock); @@ -242,11 +242,10 @@ static ssize_t led_interval_store(struct device *dev, /* impose some basic bounds on the timer interval */ if (count == size && value >= 5 && value <= 10000) { - spin_lock_bh(&trigger_data->lock); - del_timer_sync(&trigger_data->timer); + cancel_delayed_work_sync(&trigger_data->work); + spin_lock_bh(&trigger_data->lock); trigger_data->interval = msecs_to_jiffies(value); - set_baseline_state(trigger_data); /* resets timer */ spin_unlock_bh(&trigger_data->lock); @@ -268,13 +267,13 @@ static int netdev_trig_notify(struct notifier_block *nb, if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER && evt != NETDEV_CHANGENAME) return NOTIFY_DONE; + cancel_delayed_work_sync(&trigger_data->work); + spin_lock_bh(&trigger_data->lock); if (strcmp(dev->name, trigger_data->device_name)) goto done; - del_timer_sync(&trigger_data->timer); - if (evt == NETDEV_REGISTER || evt == NETDEV_CHANGENAME) { if (trigger_data->net_dev != NULL) dev_put(trigger_data->net_dev); @@ -302,9 +301,9 @@ done: } /* here's the real work! */ -static void netdev_trig_timer(unsigned long arg) +static void netdev_trig_work(struct work_struct *work) { - struct led_netdev_data *trigger_data = (struct led_netdev_data *)arg; + struct led_netdev_data *trigger_data = container_of(work, struct led_netdev_data, work.work); struct rtnl_link_stats64 *dev_stats; unsigned new_activity; struct rtnl_link_stats64 temp; @@ -343,7 +342,7 @@ static void netdev_trig_timer(unsigned long arg) } trigger_data->last_activity = new_activity; - mod_timer(&trigger_data->timer, jiffies + trigger_data->interval); + schedule_delayed_work(&trigger_data->work, trigger_data->interval); } static void netdev_trig_activate(struct led_classdev *led_cdev) @@ -360,7 +359,7 @@ static void netdev_trig_activate(struct led_classdev *led_cdev) trigger_data->notifier.notifier_call = netdev_trig_notify; trigger_data->notifier.priority = 10; - setup_timer(&trigger_data->timer, netdev_trig_timer, (unsigned long) trigger_data); + INIT_DELAYED_WORK(&trigger_data->work, netdev_trig_work); trigger_data->led_cdev = led_cdev; trigger_data->net_dev = NULL; @@ -406,8 +405,9 @@ static void netdev_trig_deactivate(struct led_classdev *led_cdev) device_remove_file(led_cdev->dev, &dev_attr_mode); device_remove_file(led_cdev->dev, &dev_attr_interval); + cancel_delayed_work_sync(&trigger_data->work); + spin_lock_bh(&trigger_data->lock); - del_timer_sync(&trigger_data->timer); if (trigger_data->net_dev) { dev_put(trigger_data->net_dev); -- 2.25.1