From 32360bf6a5d4016669c3545e7b0ec939937f5331 Mon Sep 17 00:00:00 2001 From: Dmitry Rokosov Date: Wed, 4 Sep 2024 01:39:30 +0300 Subject: leds: Introduce ordered workqueue for LEDs events instead of system_wq This allows to setup ordered workqueue for LEDs events. This may be useful, because default 'system_wq' does not guarantee execution order of each work_struct, thus for several brightness update requests (for multiple LEDs), real brightness switch could be in random order. Yes, for sysfs-based LEDs we have flush_work() call inside brightness_store() operation, but it's blocking call, so userspace caller can be blocked at a long time, which means LEDs animation stream can be broken. Ordered workqueue has the same behaviour as system_wq + flush_work(), but all scheduled works are async and userspace caller is not blocked, which it better for userspace animation scheduling. Signed-off-by: Alexey Romanov Signed-off-by: Dmitry Rokosov Link: https://lore.kernel.org/r/20240903223936.21292-1-ddrokosov@salutedevices.com [Lee: Couple of style fix-ups] Signed-off-by: Lee Jones --- include/linux/leds.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/leds.h b/include/linux/leds.h index e5968c3ed4ae..9f34b9facaad 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -171,6 +171,7 @@ struct led_classdev { int new_blink_brightness; void (*flash_resume)(struct led_classdev *led_cdev); + struct workqueue_struct *wq; /* LED workqueue */ struct work_struct set_brightness_work; int delayed_set_value; unsigned long delayed_delay_on; -- cgit v1.2.3