On 02/03/2018 10:22 PM, Jacek Anaszewski wrote:
Hi Sasha,
All 3.18, 4.4 and 4.9 also require the follow-up patch [0], similarly like autosel did it for 4.14, since this one alone breaks the other use case.
Actually after taking closer look, it turns out that the patch [0] applies cleanly only to 4.14.
4.9 requires also the patch :
eb1610b4c273 ("led: core: Fix blink_brightness setting race")
3.18 and 4.4 shouldn't have the issue since it was introduced along with LED_BLINK_SW flag added in 4.7.
Thanks, Jacek Anaszewski
[0] https://lkml.org/lkml/2018/2/3/249
On 02/03/2018 07:03 PM, Sasha Levin wrote:
From: Matthieu CASTET matthieu.castet@parrot.com
[ Upstream commit 2b83ff96f51d0b039c4561b9f95c824d7bddb85c ]
With the current code, the following sequence won't work : echo timer > trigger
echo 0 > delay_off
- at this point we call
** led_delay_off_store ** led_blink_set *** stop timer ** led_blink_setup ** led_set_software_blink *** if !delay_on, led off *** if !delay_off, set led_set_brightness_nosleep <--- LED_BLINK_SW is set but timer is stop *** otherwise start timer/set LED_BLINK_SW flag
echo xxx > brightness
- led_set_brightness
** if LED_BLINK_SW *** if brightness=0, led off *** else apply brightness if next timer <--- timer is stop, and will never apply new setting ** otherwise set led_set_brightness_nosleep
To fix that, when we delete the timer, we should clear LED_BLINK_SW.
Cc: linux-leds@vger.kernel.org Signed-off-by: Matthieu CASTET matthieu.castet@parrot.com Signed-off-by: Jacek Anaszewski jacek.anaszewski@gmail.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com
drivers/leds/led-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c index 3bce44893021..d70d4a5273b8 100644 --- a/drivers/leds/led-core.c +++ b/drivers/leds/led-core.c @@ -186,7 +186,7 @@ void led_blink_set(struct led_classdev *led_cdev, unsigned long *delay_on, unsigned long *delay_off) {
- del_timer_sync(&led_cdev->blink_timer);
- led_stop_software_blink(led_cdev);
led_cdev->flags &= ~LED_BLINK_ONESHOT; led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;