From patchwork Fri Nov 9 09:48:57 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Heiko_St=C3=BCbner?= X-Patchwork-Id: 10675641 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7F48914E2 for ; Fri, 9 Nov 2018 09:49:14 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6FD132E63D for ; Fri, 9 Nov 2018 09:49:14 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 646D62E64A; Fri, 9 Nov 2018 09:49:14 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id BBABF2E63D for ; Fri, 9 Nov 2018 09:49:13 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id ACE4B6E379; Fri, 9 Nov 2018 09:49:12 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from gloria.sntech.de (gloria.sntech.de [185.11.138.130]) by gabe.freedesktop.org (Postfix) with ESMTPS id A30AD6E379 for ; Fri, 9 Nov 2018 09:49:10 +0000 (UTC) Received: from p5b2f294a.dip0.t-ipconnect.de ([91.47.41.74] helo=phil.lan) by gloria.sntech.de with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.89) (envelope-from ) id 1gL3PX-0007fH-NQ; Fri, 09 Nov 2018 10:49:07 +0100 From: Heiko Stuebner To: lee.jones@linaro.org, daniel.thompson@linaro.org, jingoohan1@gmail.com Subject: [PATCH] backlight: pwm_bl: re-add driver internal enabled tracking Date: Fri, 9 Nov 2018 10:48:57 +0100 Message-Id: <20181109094857.27079-1-heiko@sntech.de> X-Mailer: git-send-email 2.18.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: enric.balletbo@collabora.com, linux-pwm@vger.kernel.org, thierry.reding@gmail.com, dri-devel@lists.freedesktop.org MIME-Version: 1.0 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP Commit e6bcca0890b9 ("backlight: pwm_bl: Switch to using "atomic" PWM API") removed the driver internal enabled tracking in favor of simply checking the pwm state. This can lead to issues as all of gpio-, regulator- and pwm-state are used to determine the initial state and the bootloader or kernel can leave them in an inconsistent state at boot. In my case on rk3399-kevin, the pwm backlight is build as module and the kernel disables the supply regulator as unused while keeping the pwm running thus pwm_bl calling pwm_backlight_power_off() during probe and creating an unmatched regulator-disable call, as it never got enabled from the pwm-bl before. To prevent these consistency issues, reintroduce the driver-internal tracking of the enabled state. Fixes: e6bcca0890b9 ("backlight: pwm_bl: Switch to using "atomic" PWM API") Signed-off-by: Heiko Stuebner Reviewed-by: Enric Balletbo i Serra Acked-by: Uwe Kleine-König Acked-by: Thierry Reding Acked-by: Daniel Thompson --- drivers/video/backlight/pwm_bl.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index 678b27063198..bcd08b41765d 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -30,6 +30,7 @@ struct pwm_bl_data { struct device *dev; unsigned int lth_brightness; unsigned int *levels; + bool enabled; struct regulator *power_supply; struct gpio_desc *enable_gpio; unsigned int scale; @@ -50,7 +51,7 @@ static void pwm_backlight_power_on(struct pwm_bl_data *pb) int err; pwm_get_state(pb->pwm, &state); - if (state.enabled) + if (pb->enabled) return; err = regulator_enable(pb->power_supply); @@ -65,6 +66,8 @@ static void pwm_backlight_power_on(struct pwm_bl_data *pb) if (pb->enable_gpio) gpiod_set_value_cansleep(pb->enable_gpio, 1); + + pb->enabled = true; } static void pwm_backlight_power_off(struct pwm_bl_data *pb) @@ -72,7 +75,7 @@ static void pwm_backlight_power_off(struct pwm_bl_data *pb) struct pwm_state state; pwm_get_state(pb->pwm, &state); - if (!state.enabled) + if (!pb->enabled) return; if (pb->enable_gpio) @@ -86,6 +89,7 @@ static void pwm_backlight_power_off(struct pwm_bl_data *pb) pwm_apply_state(pb->pwm, &state); regulator_disable(pb->power_supply); + pb->enabled = false; } static int compute_duty_cycle(struct pwm_bl_data *pb, int brightness) @@ -483,6 +487,7 @@ static int pwm_backlight_probe(struct platform_device *pdev) pb->check_fb = data->check_fb; pb->exit = data->exit; pb->dev = &pdev->dev; + pb->enabled = false; pb->post_pwm_on_delay = data->post_pwm_on_delay; pb->pwm_off_delay = data->pwm_off_delay;