From 2b1129a7bafce7a6eb0ff8fd5d397cbbcc7c00ac Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= Date: Wed, 23 Dec 2015 15:45:43 +0000 Subject: [PATCH] ledtrig-netdev: drop locking from timer callback function MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We may just delete timer on every trigger update and then start it again if needed. This will let us avoid both: races and locking in frequently called timer callback. Signed-off-by: Rafał Miłecki SVN-Revision: 47987 --- .../files/drivers/leds/ledtrig-netdev.c | 24 ++++++++++--------- 1 file changed, 13 insertions(+), 11 deletions(-) diff --git a/target/linux/generic/files/drivers/leds/ledtrig-netdev.c b/target/linux/generic/files/drivers/leds/ledtrig-netdev.c index 018392a920..4e0844a597 100644 --- a/target/linux/generic/files/drivers/leds/ledtrig-netdev.c +++ b/target/linux/generic/files/drivers/leds/ledtrig-netdev.c @@ -92,8 +92,6 @@ static void set_baseline_state(struct led_netdev_data *trigger_data) if ((trigger_data->mode & (MODE_TX | MODE_RX)) != 0 && trigger_data->link_up) mod_timer(&trigger_data->timer, jiffies + trigger_data->interval); - else - del_timer(&trigger_data->timer); } static ssize_t led_device_name_show(struct device *dev, @@ -119,6 +117,7 @@ static ssize_t led_device_name_store(struct device *dev, return -EINVAL; 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') @@ -129,10 +128,11 @@ static ssize_t led_device_name_store(struct device *dev, trigger_data->net_dev = dev_get_by_name(&init_net, trigger_data->device_name); if (trigger_data->net_dev != NULL) trigger_data->link_up = (dev_get_flags(trigger_data->net_dev) & IFF_LOWER_UP) != 0; - set_baseline_state(trigger_data); /* updates LEDs, may start timers */ } + set_baseline_state(trigger_data); spin_unlock_bh(&trigger_data->lock); + return size; } @@ -200,7 +200,10 @@ static ssize_t led_mode_store(struct device *dev, return -EINVAL; spin_lock_bh(&trigger_data->lock); + del_timer_sync(&trigger_data->timer); + trigger_data->mode = new_mode; + set_baseline_state(trigger_data); spin_unlock_bh(&trigger_data->lock); @@ -238,9 +241,13 @@ 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); + trigger_data->interval = msecs_to_jiffies(value); + set_baseline_state(trigger_data); /* resets timer */ spin_unlock_bh(&trigger_data->lock); + ret = count; } @@ -260,6 +267,7 @@ static int netdev_trig_notify(struct notifier_block *nb, return NOTIFY_DONE; spin_lock_bh(&trigger_data->lock); + del_timer_sync(&trigger_data->timer); if (strcmp(dev->name, trigger_data->device_name)) goto done; @@ -297,12 +305,10 @@ static void netdev_trig_timer(unsigned long arg) unsigned new_activity; struct rtnl_link_stats64 temp; - spin_lock(&trigger_data->lock); - if (!trigger_data->link_up || !trigger_data->net_dev || (trigger_data->mode & (MODE_TX | MODE_RX)) == 0) { /* we don't need to do timer work, just reflect link state. */ led_set_brightness(trigger_data->led_cdev, ((trigger_data->mode & MODE_LINK) != 0 && trigger_data->link_up) ? LED_FULL : LED_OFF); - goto no_restart; + return; } dev_stats = dev_get_stats(trigger_data->net_dev, &temp); @@ -334,9 +340,6 @@ static void netdev_trig_timer(unsigned long arg) trigger_data->last_activity = new_activity; mod_timer(&trigger_data->timer, jiffies + trigger_data->interval); - -no_restart: - spin_unlock(&trigger_data->lock); } static void netdev_trig_activate(struct led_classdev *led_cdev) @@ -400,6 +403,7 @@ static void netdev_trig_deactivate(struct led_classdev *led_cdev) device_remove_file(led_cdev->dev, &dev_attr_interval); spin_lock_bh(&trigger_data->lock); + del_timer_sync(&trigger_data->timer); if (trigger_data->net_dev) { dev_put(trigger_data->net_dev); @@ -408,8 +412,6 @@ static void netdev_trig_deactivate(struct led_classdev *led_cdev) spin_unlock_bh(&trigger_data->lock); - del_timer_sync(&trigger_data->timer); - kfree(trigger_data); } }