On Wed, Jun 25, 2014 at 03:52:33PM -0700, Bryan Wu wrote:
> On Sat, Jun 14, 2014 at 2:21 AM, Vincent Donnefort <vdonnefort@xxxxxxxxx> wrote:
> > From: Vincent Donnefort <vdonnefort@xxxxxxxxx>
> >
> > 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.
> >
>
> Actually I prefer to use workqueue here, too. But I'd like to know
> more details about the error you mentioned here.
There is for now none driver using pinctrl, this example was bad since taken on a
driver which has not been merged yet.
However the same problem appears for drivers which needs gpio_cansleep
and so needs their own workqueue.
>
> Any test case?
>
> Thanks,
> -Bryan
>
> > Signed-off-by: Vincent Donnefort <vdonnefort@xxxxxxxxx>
> >
> > diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
> > index f37d63c..0567a24 100644
> > --- 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)
> > @@ -230,9 +232,7 @@ 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 71b40d3..4bb1168 100644
> > --- 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 0287ab2..89af7b8 100644
> > --- 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;
> > @@ -67,7 +66,7 @@ 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;
> > --
> > 1.9.1
> >
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