led: core: Fix blink_brightness setting race
All 3 of led_timer_func, led_set_brightness and led_set_software_blink
set blink_brightness. If led_timer_func or led_set_software_blink race
with led_set_brightness they may end up overwriting the new
blink_brightness. The new atomic work_flags does not protect against
this as it just protects the flags and not blink_brightness.
This commit introduces a new new_blink_brightness value which gets
set by led_set_brightness and read by led_timer_func on LED on, fixing
this.
Dealing with the new brightness at LED on time, makes the new
brightness apply sooner, which also fixes a led_set_brightness which
happens while a oneshot blink which ends in LED on is running not
getting applied.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
diff --git a/include/linux/leds.h b/include/linux/leds.h
index 21c598b..569cb53 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -93,6 +93,7 @@ struct led_classdev {
unsigned long blink_delay_on, blink_delay_off;
struct timer_list blink_timer;
int blink_brightness;
+ int new_blink_brightness;
void (*flash_resume)(struct led_classdev *led_cdev);
struct work_struct set_brightness_work;