diff options
| -rw-r--r-- | drivers/leds/trigger/ledtrig-tty.c | 59 |
1 files changed, 30 insertions, 29 deletions
diff --git a/drivers/leds/trigger/ledtrig-tty.c b/drivers/leds/trigger/ledtrig-tty.c index 3e69a7bde928..b16bd9cb9713 100644 --- a/drivers/leds/trigger/ledtrig-tty.c +++ b/drivers/leds/trigger/ledtrig-tty.c @@ -1,5 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 +#include <linux/completion.h> #include <linux/delay.h> #include <linux/leds.h> #include <linux/module.h> @@ -12,15 +13,23 @@ struct ledtrig_tty_data { struct led_classdev *led_cdev; struct delayed_work dwork; - struct mutex mutex; + struct completion sysfs; const char *ttyname; struct tty_struct *tty; int rx, tx; }; -static void ledtrig_tty_restart(struct ledtrig_tty_data *trigger_data) +static int ledtrig_tty_wait_for_completion(struct device *dev) { - schedule_delayed_work(&trigger_data->dwork, 0); + struct ledtrig_tty_data *trigger_data = led_trigger_get_drvdata(dev); + int ret; + + ret = wait_for_completion_timeout(&trigger_data->sysfs, + msecs_to_jiffies(LEDTRIG_TTY_INTERVAL * 20)); + if (ret == 0) + return -ETIMEDOUT; + + return ret; } static ssize_t ttyname_show(struct device *dev, @@ -28,14 +37,16 @@ static ssize_t ttyname_show(struct device *dev, { struct ledtrig_tty_data *trigger_data = led_trigger_get_drvdata(dev); ssize_t len = 0; + int completion; - mutex_lock(&trigger_data->mutex); + reinit_completion(&trigger_data->sysfs); + completion = ledtrig_tty_wait_for_completion(dev); + if (completion < 0) + return completion; if (trigger_data->ttyname) len = sprintf(buf, "%s\n", trigger_data->ttyname); - mutex_unlock(&trigger_data->mutex); - return len; } @@ -46,7 +57,7 @@ static ssize_t ttyname_store(struct device *dev, struct ledtrig_tty_data *trigger_data = led_trigger_get_drvdata(dev); char *ttyname; ssize_t ret = size; - bool running; + int completion; if (size > 0 && buf[size - 1] == '\n') size -= 1; @@ -59,9 +70,10 @@ static ssize_t ttyname_store(struct device *dev, ttyname = NULL; } - mutex_lock(&trigger_data->mutex); - - running = trigger_data->ttyname != NULL; + reinit_completion(&trigger_data->sysfs); + completion = ledtrig_tty_wait_for_completion(dev); + if (completion < 0) + return completion; kfree(trigger_data->ttyname); tty_kref_put(trigger_data->tty); @@ -69,11 +81,6 @@ static ssize_t ttyname_store(struct device *dev, trigger_data->ttyname = ttyname; - mutex_unlock(&trigger_data->mutex); - - if (ttyname && !running) - ledtrig_tty_restart(trigger_data); - return ret; } static DEVICE_ATTR_RW(ttyname); @@ -85,13 +92,8 @@ static void ledtrig_tty_work(struct work_struct *work) struct serial_icounter_struct icount; int ret; - mutex_lock(&trigger_data->mutex); - - if (!trigger_data->ttyname) { - /* exit without rescheduling */ - mutex_unlock(&trigger_data->mutex); - return; - } + if (!trigger_data->ttyname) + goto out; /* try to get the tty corresponding to $ttyname */ if (!trigger_data->tty) { @@ -116,11 +118,8 @@ static void ledtrig_tty_work(struct work_struct *work) } ret = tty_get_icount(trigger_data->tty, &icount); - if (ret) { - dev_info(trigger_data->tty->dev, "Failed to get icount, stopped polling\n"); - mutex_unlock(&trigger_data->mutex); - return; - } + if (ret) + goto out; if (icount.rx != trigger_data->rx || icount.tx != trigger_data->tx) { @@ -134,7 +133,7 @@ static void ledtrig_tty_work(struct work_struct *work) } out: - mutex_unlock(&trigger_data->mutex); + complete_all(&trigger_data->sysfs); schedule_delayed_work(&trigger_data->dwork, msecs_to_jiffies(LEDTRIG_TTY_INTERVAL * 2)); } @@ -157,7 +156,9 @@ static int ledtrig_tty_activate(struct led_classdev *led_cdev) INIT_DELAYED_WORK(&trigger_data->dwork, ledtrig_tty_work); trigger_data->led_cdev = led_cdev; - mutex_init(&trigger_data->mutex); + init_completion(&trigger_data->sysfs); + + schedule_delayed_work(&trigger_data->dwork, 0); return 0; } |