linux-kernel - [PATCH AUTOSEL for 4.9 28/52] led: core: Fix brightness setting when setting delay

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Message-ID: <20180203180303.8490-28-alexander.levin@microsoft.com>
Date:   Sat, 3 Feb 2018 18:03:49 +0000
From:   Sasha Levin <Alexander.Levin@...rosoft.com>
To:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "stable@...r.kernel.org" <stable@...r.kernel.org>
CC:     Matthieu CASTET <matthieu.castet@...rot.com>,
        "linux-leds@...r.kernel.org" <linux-leds@...r.kernel.org>,
        Jacek Anaszewski <jacek.anaszewski@...il.com>,
        Sasha Levin <Alexander.Levin@...rosoft.com>
Subject: [PATCH AUTOSEL for 4.9 28/52] led: core: Fix brightness setting when
 setting delay_off=0

From: Matthieu CASTET <matthieu.castet@...rot.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@...r.kernel.org
Signed-off-by: Matthieu CASTET <matthieu.castet@...rot.com>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@...il.com>
Signed-off-by: Sasha Levin <alexander.levin@...rosoft.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;
-- 
2.11.0