leds: convert blink timer to workqueue

This patch converts the blink timer from led-core to workqueue which is more
suitable for this kind of non-priority operations. Moreover, timer may lead to
errors when a LED setting function use a scheduling function such as pinctrl
which is using mutex.

Signed-off-by: Vincent Donnefort <vdonnefort@gmail.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>

diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index aa29198fca3e2b2c892268eb2549444b1beb499c..129729d35478bf5934cb69c90a688a9c43399759 100644 (file)
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -15,10 +15,10 @@
 #include <linux/list.h>
 #include <linux/spinlock.h>
 #include <linux/device.h>
-#include <linux/timer.h>
 #include <linux/err.h>
 #include <linux/ctype.h>
 #include <linux/leds.h>
+#include <linux/workqueue.h>
 #include "leds.h"
 
 static struct class *leds_class;
@@ -97,9 +97,10 @@ static const struct attribute_group *led_groups[] = {
        NULL,
 };
 
-static void led_timer_function(unsigned long data)
+static void led_work_function(struct work_struct *ws)
 {
-       struct led_classdev *led_cdev = (void *)data;
+       struct led_classdev *led_cdev =
+               container_of(ws, struct led_classdev, blink_work.work);
        unsigned long brightness;
        unsigned long delay;
 
@@ -143,7 +144,8 @@ static void led_timer_function(unsigned long data)
                }
        }
 
-       mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay));
+       queue_delayed_work(system_wq, &led_cdev->blink_work,
+                          msecs_to_jiffies(delay));
 }
 
 static void set_brightness_delayed(struct work_struct *ws)
@@ -231,9 +233,7 @@ int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
 
        INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed);
 
-       init_timer(&led_cdev->blink_timer);
-       led_cdev->blink_timer.function = led_timer_function;
-       led_cdev->blink_timer.data = (unsigned long)led_cdev;
+       INIT_DELAYED_WORK(&led_cdev->blink_work, led_work_function);
 
 #ifdef CONFIG_LEDS_TRIGGERS
        led_trigger_set_default(led_cdev);

diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c
index 71b40d3bf77604e32829f391b6e804bbeefb0cf1..4bb116867b88af7249c1576e614e8ad0685f7945 100644 (file)
--- a/drivers/leds/led-core.c
+++ b/drivers/leds/led-core.c
@@ -16,6 +16,7 @@
 #include <linux/module.h>
 #include <linux/rwsem.h>
 #include <linux/leds.h>
+#include <linux/workqueue.h>
 #include "leds.h"
 
 DECLARE_RWSEM(leds_list_lock);
@@ -51,7 +52,7 @@ static void led_set_software_blink(struct led_classdev *led_cdev,
                return;
        }
 
-       mod_timer(&led_cdev->blink_timer, jiffies + 1);
+       queue_delayed_work(system_wq, &led_cdev->blink_work, 1);
 }
 
 
@@ -75,7 +76,7 @@ void led_blink_set(struct led_classdev *led_cdev,
                   unsigned long *delay_on,
                   unsigned long *delay_off)
 {
-       del_timer_sync(&led_cdev->blink_timer);
+       cancel_delayed_work_sync(&led_cdev->blink_work);
 
        led_cdev->flags &= ~LED_BLINK_ONESHOT;
        led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;
@@ -90,7 +91,7 @@ void led_blink_set_oneshot(struct led_classdev *led_cdev,
                           int invert)
 {
        if ((led_cdev->flags & LED_BLINK_ONESHOT) &&
-            timer_pending(&led_cdev->blink_timer))
+            delayed_work_pending(&led_cdev->blink_work))
                return;
 
        led_cdev->flags |= LED_BLINK_ONESHOT;
@@ -107,7 +108,7 @@ EXPORT_SYMBOL(led_blink_set_oneshot);
 
 void led_stop_software_blink(struct led_classdev *led_cdev)
 {
-       del_timer_sync(&led_cdev->blink_timer);
+       cancel_delayed_work_sync(&led_cdev->blink_work);
        led_cdev->blink_delay_on = 0;
        led_cdev->blink_delay_off = 0;
 }
@@ -116,7 +117,7 @@ EXPORT_SYMBOL_GPL(led_stop_software_blink);
 void led_set_brightness(struct led_classdev *led_cdev,
                        enum led_brightness brightness)
 {
-       /* delay brightness setting if need to stop soft-blink timer */
+       /* delay brightness setting if need to stop soft-blink work */
        if (led_cdev->blink_delay_on || led_cdev->blink_delay_off) {
                led_cdev->delayed_set_value = brightness;
                schedule_work(&led_cdev->set_brightness_work);

diff --git a/include/linux/leds.h b/include/linux/leds.h
index e436864721971c81383a323bf3951e19632475a0..6a599dce7f9d4678e4f6f7f082514308f0636942 100644 (file)
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -15,7 +15,6 @@
 #include <linux/list.h>
 #include <linux/spinlock.h>
 #include <linux/rwsem.h>
-#include <linux/timer.h>
 #include <linux/workqueue.h>
 
 struct device;
@@ -69,7 +68,7 @@ struct led_classdev {
        const char              *default_trigger;       /* Trigger to use */
 
        unsigned long            blink_delay_on, blink_delay_off;
-       struct timer_list        blink_timer;
+       struct delayed_work      blink_work;
        int                      blink_brightness;
 
        struct work_struct      set_brightness_work;