Hi Jacek,
On 20/09/2019 23:10, Jacek Anaszewski wrote:
Hi Jean,
On 9/20/19 2:25 PM, Jean-Jacques Hiblot wrote:
Making led_set_brightness_sync() use led_set_brightness_nosleep() has 2
advantages:
- works for LED controllers that do not provide brightness_set_blocking()
- When the blocking callback is used, it uses the workqueue to update the
LED state, removing the need for mutual exclusion between
led_set_brightness_sync() and set_brightness_delayed().
And third:
- it compromises the "sync" part of the function name :-)
Making it sync is the role of the flush_work() function. It waits until
the deferred work has been done.
JJ
This function has been introduced specifically to be blocking
and have the immediate effect. Its sole client is
drivers/media/v4l2-core/v4l2-flash-led-class.c.
Signed-off-by: Jean-Jacques Hiblot <jjhiblot@xxxxxx>
---
drivers/leds/led-core.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c
index f1f718dbe0f8..50e28a8f9357 100644
--- a/drivers/leds/led-core.c
+++ b/drivers/leds/led-core.c
@@ -294,15 +294,17 @@ EXPORT_SYMBOL_GPL(led_set_brightness_nosleep);
int led_set_brightness_sync(struct led_classdev *led_cdev,
enum led_brightness value)
{
+ int ret;
+
if (led_cdev->blink_delay_on || led_cdev->blink_delay_off)
return -EBUSY;
- led_cdev->brightness = min(value, led_cdev->max_brightness);
-
- if (led_cdev->flags & LED_SUSPENDED)
- return 0;
+ ret = led_set_brightness_nosleep(led_cdev, value);
+ if (!ret)
+ return ret;
- return __led_set_brightness_blocking(led_cdev, led_cdev->brightness);
+ flush_work(&led_cdev->set_brightness_work);
+ return 0;
}
EXPORT_SYMBOL_GPL(led_set_brightness_sync);
