Delay execution of led_set_brightness() if need to stop soft-blink
timer.
This allows led_set_brightness to be called in hard-irq context even if
soft-blink was activated on that LED.
Signed-off-by: Fabio Baltieri <fabio.baltieri@xxxxxxxxx>
Cc: Pawel Moll <pawel.moll@xxxxxxx>
Cc: Bryan Wu <bryan.wu@xxxxxxxxxxxxx>
---
Hello Bryan,
this version fixes the race in trigger change code and adds proper cleanup
functions in unregister code path.
Also, stop_blink code is now in a separe function declared in the local include
file - it should not be needed for external triggers as the stop happens
automatically for triggers trough set_brightess and trigger_event, through
trigger change and unload functions requires it to be executed undelayed to
work properly.
I re-run all the test I had with this patch, including:
- setting/resetting/changing trigger from timer/oneshot and none (which was I
broke in V1)
- mixed trigger from hard-irq: that's a snipped of the hacked code I used:
if ((jiffies / HZ / 2) & 1)
led_trigger_blink_oneshot(ledtrig_ide,
&ide_blink_delay, &ide_blink_delay, 0);
if ((jiffies / HZ / 4) & 1)
led_trigger_event(ledtrig_ide, 100);
if ((jiffies / HZ / 8) & 1)
led_trigger_event(ledtrig_ide, 0);
called repetedly from my sound-card irq handler while playing. The result is
something like: 2s off, 2s blink, 4s on, 8s off.
- mixed set_blink/set_brightness from the power_supply trigger (which was one
who needed the original patch)
- the CAN trigger I'm working on
- some load/unload of my LED device driver
- a bit of ftrace :-)
the only thing I'm missing is testing on a real SMP system (I got an UP with
CONFIG_SMP=y), but the critical part is unchanged so that should be ok.
If that patch is ok, I think that we may also unify triggers to use only
led_set_brightness in the future, as that now falls back automatically to
__led_set_brightness if only direct-setting is used.
Would you please consider this patch to replace the v1 currently in your
for-next branch?
Fabio
drivers/leds/led-class.c | 15 +++++++++++++++
drivers/leds/led-core.c | 16 +++++++++++++---
drivers/leds/led-triggers.c | 4 +++-
drivers/leds/leds.h | 2 ++
include/linux/leds.h | 4 ++++
5 files changed, 37 insertions(+), 4 deletions(-)
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index c599095..48cce18 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -124,6 +124,16 @@ static void led_timer_function(unsigned long data)
mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay));
}
+static void set_brightness_delayed(struct work_struct *ws)
+{
+ struct led_classdev *led_cdev =
+ container_of(ws, struct led_classdev, set_brightness_work);
+
+ led_stop_software_blink(led_cdev);
+
+ __led_set_brightness(led_cdev, led_cdev->delayed_set_value);
+}
+
/**
* led_classdev_suspend - suspend an led_classdev.
* @led_cdev: the led_classdev to suspend.
@@ -191,6 +201,8 @@ int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
led_update_brightness(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;
@@ -221,7 +233,10 @@ void led_classdev_unregister(struct led_classdev *led_cdev)
up_write(&led_cdev->trigger_lock);
#endif
+ cancel_work_sync(&led_cdev->set_brightness_work);
+
/* Stop blinking */
+ led_stop_software_blink(led_cdev);
led_set_brightness(led_cdev, LED_OFF);
device_unregister(led_cdev->dev);
diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c
index 2ab05af..ce8921a 100644
--- a/drivers/leds/led-core.c
+++ b/drivers/leds/led-core.c
@@ -103,13 +103,23 @@ void led_blink_set_oneshot(struct led_classdev *led_cdev,
}
EXPORT_SYMBOL(led_blink_set_oneshot);
-void led_set_brightness(struct led_classdev *led_cdev,
- enum led_brightness brightness)
+void led_stop_software_blink(struct led_classdev *led_cdev)
{
- /* stop and clear soft-blink timer */
del_timer_sync(&led_cdev->blink_timer);
led_cdev->blink_delay_on = 0;
led_cdev->blink_delay_off = 0;
+}
+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 */
+ if (led_cdev->blink_delay_on || led_cdev->blink_delay_off) {
+ led_cdev->delayed_set_value = brightness;
+ schedule_work(&led_cdev->set_brightness_work);
+ return;
+ }
__led_set_brightness(led_cdev, brightness);
}
diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
index 363975b..b53bf54 100644
--- a/drivers/leds/led-triggers.c
+++ b/drivers/leds/led-triggers.c
@@ -109,6 +109,8 @@ void led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
list_del(&led_cdev->trig_list);
write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock,
flags);
+ cancel_work_sync(&led_cdev->set_brightness_work);
+ led_stop_software_blink(led_cdev);
if (led_cdev->trigger->deactivate)
led_cdev->trigger->deactivate(led_cdev);
led_cdev->trigger = NULL;
@@ -224,7 +226,7 @@ void led_trigger_event(struct led_trigger *trig,
struct led_classdev *led_cdev;
led_cdev = list_entry(entry, struct led_classdev, trig_list);
- __led_set_brightness(led_cdev, brightness);
+ led_set_brightness(led_cdev, brightness);
}
read_unlock(&trig->leddev_list_lock);
}
diff --git a/drivers/leds/leds.h b/drivers/leds/leds.h
index d02acd4..4c50365 100644
--- a/drivers/leds/leds.h
+++ b/drivers/leds/leds.h
@@ -32,6 +32,8 @@ static inline int led_get_brightness(struct led_classdev *led_cdev)
return led_cdev->brightness;
}
+void led_stop_software_blink(struct led_classdev *led_cdev);
+
extern struct rw_semaphore leds_list_lock;
extern struct list_head leds_list;
diff --git a/include/linux/leds.h b/include/linux/leds.h
index 3aade1d..5676197 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -16,6 +16,7 @@
#include <linux/spinlock.h>
#include <linux/rwsem.h>
#include <linux/timer.h>
+#include <linux/workqueue.h>
struct device;
/*
@@ -69,6 +70,9 @@ struct led_classdev {
struct timer_list blink_timer;
int blink_brightness;
+ struct work_struct set_brightness_work;
+ int delayed_set_value;
+
#ifdef CONFIG_LEDS_TRIGGERS
/* Protects the trigger data below */
struct rw_semaphore trigger_lock;
--
1.7.11.rc1.9.gf623ca1.dirty
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