From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jacek Anaszewski Subject: Re: [PATCH AUTOSEL for 4.9 28/52] led: core: Fix brightness setting when setting delay_off=0 Date: Sat, 3 Feb 2018 23:34:23 +0100 Message-ID: References: <20180203180303.8490-1-alexander.levin@microsoft.com> <20180203180303.8490-28-alexander.levin@microsoft.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Return-path: Received: from mail-wm0-f67.google.com ([74.125.82.67]:34271 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752688AbeBCWfh (ORCPT ); Sat, 3 Feb 2018 17:35:37 -0500 In-Reply-To: Sender: linux-leds-owner@vger.kernel.org List-Id: linux-leds@vger.kernel.org To: Sasha Levin , "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Cc: Matthieu CASTET , "linux-leds@vger.kernel.org" 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 >> >> [ 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 >> Signed-off-by: Jacek Anaszewski >> Signed-off-by: Sasha Levin >> --- >> 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; >> >