From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 11C623307B for ; Wed, 15 Nov 2023 20:56:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="R5dguvf5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B7555C4E777; Wed, 15 Nov 2023 20:56:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1700081778; bh=slFDfMwxszxP70hUGLJ+ZoVUfGys8EWN1cf0bjn3WxI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=R5dguvf5AoUeSV3R4Ky8jngvFco/PDKT34+f7jWQxOB2+TyqywIfl7OiNlKY3BaDC SO3bh4Q9VfCqBSuqcyqbyy27IJxQTj0rEDZJa8tLq7V9+4e0yNVr+Eo6K2Jc0RmXes V25V18SNxC+AVK4ET6o07K8XXJ2p2hXe3NCl9sNQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Rogan Dawes , Fabio Estevam , =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , Lee Jones , Sasha Levin Subject: [PATCH 5.10 120/191] leds: pwm: Dont disable the PWM when the LED should be off Date: Wed, 15 Nov 2023 15:46:35 -0500 Message-ID: <20231115204651.739010602@linuxfoundation.org> X-Mailer: git-send-email 2.42.1 In-Reply-To: <20231115204644.490636297@linuxfoundation.org> References: <20231115204644.490636297@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Uwe Kleine-König [ Upstream commit 76fe464c8e64e71b2e4af11edeef0e5d85eeb6aa ] Disabling a PWM (i.e. calling pwm_apply_state with .enabled = false) gives no guarantees what the PWM output does. It might freeze where it currently is, or go in a High-Z state or drive the active or inactive state, it might even continue to toggle. To ensure that the LED gets really disabled, don't disable the PWM even when .duty_cycle is zero. This fixes disabling a leds-pwm LED on i.MX28. The PWM on this SoC is one of those that freezes its output on disable, so if you disable an LED that is full on, it stays on. If you disable a LED with half brightness it goes off in 50% of the cases and full on in the other 50%. Fixes: 41c42ff5dbe2 ("leds: simple driver for pwm driven LEDs") Reported-by: Rogan Dawes Reported-by: Fabio Estevam Signed-off-by: Uwe Kleine-König Reviewed-by: Fabio Estevam Link: https://lore.kernel.org/r/20230922192834.1695727-1-u.kleine-koenig@pengutronix.de Signed-off-by: Lee Jones Signed-off-by: Sasha Levin --- drivers/leds/leds-pwm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c index f53f9309ca6cc..f4c0507becb31 100644 --- a/drivers/leds/leds-pwm.c +++ b/drivers/leds/leds-pwm.c @@ -51,7 +51,7 @@ static int led_pwm_set(struct led_classdev *led_cdev, duty = led_dat->pwmstate.period - duty; led_dat->pwmstate.duty_cycle = duty; - led_dat->pwmstate.enabled = duty > 0; + led_dat->pwmstate.enabled = true; return pwm_apply_state(led_dat->pwm, &led_dat->pwmstate); } -- 2.42.0