From patchwork Mon Oct 9 09:32:23 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= X-Patchwork-Id: 731195 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id ADEACE95A91 for ; Mon, 9 Oct 2023 09:32:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345695AbjJIJcj (ORCPT ); Mon, 9 Oct 2023 05:32:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48548 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345449AbjJIJci (ORCPT ); Mon, 9 Oct 2023 05:32:38 -0400 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [IPv6:2a0a:edc0:2:b01:1d::104]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2F58B94 for ; Mon, 9 Oct 2023 02:32:37 -0700 (PDT) Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1qpmcq-0008RZ-Jd; Mon, 09 Oct 2023 11:32:32 +0200 Received: from [2a0a:edc0:0:900:1d::77] (helo=ptz.office.stw.pengutronix.de) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1qpmco-000NZy-UD; Mon, 09 Oct 2023 11:32:30 +0200 Received: from ukl by ptz.office.stw.pengutronix.de with local (Exim 4.94.2) (envelope-from ) id 1qpmco-00C59f-Kj; Mon, 09 Oct 2023 11:32:30 +0200 From: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= To: Lee Jones , Daniel Thompson , Jingoo Han Cc: Aisheng Dong , linux-pwm@vger.kernel.org, linux-fbdev@vger.kernel.org, Helge Deller , dri-devel@lists.freedesktop.org, Thierry Reding , kernel@pengutronix.de Subject: [PATCH v4] backlight: pwm_bl: Disable PWM on shutdown, suspend and remove Date: Mon, 9 Oct 2023 11:32:23 +0200 Message-Id: <20231009093223.227286-1-u.kleine-koenig@pengutronix.de> X-Mailer: git-send-email 2.40.1 MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2987; i=u.kleine-koenig@pengutronix.de; h=from:subject; bh=ukp03GXhJGGhriRo81oTqb+ZF09mBJI1HDBsdlZDDEw=; b=owEBbQGS/pANAwAKAY+A+1h9Ev5OAcsmYgBlI8imhPFLFc7G9DQzsmEVrBtK7ni6oOsoVVU0d du0W4DICtGJATMEAAEKAB0WIQQ/gaxpOnoeWYmt/tOPgPtYfRL+TgUCZSPIpgAKCRCPgPtYfRL+ TpelB/9veiKkWgBLSFdRf8C/mZU536ZliA4SH6xEfVnniFW/RGorUdbDglV1YQkTaUbtOb6EwCT WKwjQ0OCOnwbxoL6cxSDcUKVgLnHh9wOFP4dnnosQ3thzE83HFaiCLJLNLvWWHzsQIQOTisdCIM FGESqKYG9TSdjVfI/Y8mQo2jTmwP1IdFUFfrU1P0GYum55T8xK8peNaSK1fP6T9/lDIlO6CfeOo 1tjTEGqLjX49b1xNgegMOHzAfkeMg0EETle7IAeCSy9E+x5ajTvgbaBASBH4weevYfseX2h7UR8 uEW0PNIhm4irmPEbl9vEaBh8NUQ6nYUD3/+l3mjsy7kedtKc X-Developer-Key: i=u.kleine-koenig@pengutronix.de; a=openpgp; fpr=0D2511F322BFAB1C1580266BE2DCDD9132669BD6 X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: ukl@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-fbdev@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org Since commit 00e7e698bff1 ("backlight: pwm_bl: Configure pwm only once per backlight toggle") calling pwm_backlight_power_off() doesn't disable the PWM any more. However this is necessary to suspend because PWM drivers usually refuse to suspend if they are still enabled. Also adapt shutdown and remove callbacks to disable the PWM for similar reasons. Fixes: 00e7e698bff1 ("backlight: pwm_bl: Configure pwm only once per backlight toggle") Reported-by: Aisheng Dong Tested-by: Aisheng Dong Signed-off-by: Uwe Kleine-König --- Hello, Changes since v3 (available at https://lore.kernel.org/linux-fbdev/20230926150116.2124384-1-u.kleine-koenig@pengutronix.de): - Fix buildfailure identified by the kernel test robot. (*Sigh*, that's what you get if you improve a patch without build testing ...) - Fix the Subject to also mention "remove". Best regards Uwe drivers/video/backlight/pwm_bl.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) base-commit: 0bb80ecc33a8fb5a682236443c1e740d5c917d1d diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index a51fbab96368..289bd9ce4d36 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -626,9 +626,14 @@ static void pwm_backlight_remove(struct platform_device *pdev) { struct backlight_device *bl = platform_get_drvdata(pdev); struct pwm_bl_data *pb = bl_get_data(bl); + struct pwm_state state; backlight_device_unregister(bl); pwm_backlight_power_off(pb); + pwm_get_state(pb->pwm, &state); + state.duty_cycle = 0; + state.enabled = false; + pwm_apply_state(pb->pwm, &state); if (pb->exit) pb->exit(&pdev->dev); @@ -638,8 +643,13 @@ static void pwm_backlight_shutdown(struct platform_device *pdev) { struct backlight_device *bl = platform_get_drvdata(pdev); struct pwm_bl_data *pb = bl_get_data(bl); + struct pwm_state state; pwm_backlight_power_off(pb); + pwm_get_state(pb->pwm, &state); + state.duty_cycle = 0; + state.enabled = false; + pwm_apply_state(pb->pwm, &state); } #ifdef CONFIG_PM_SLEEP @@ -647,12 +657,24 @@ static int pwm_backlight_suspend(struct device *dev) { struct backlight_device *bl = dev_get_drvdata(dev); struct pwm_bl_data *pb = bl_get_data(bl); + struct pwm_state state; if (pb->notify) pb->notify(pb->dev, 0); pwm_backlight_power_off(pb); + /* + * Note that disabling the PWM doesn't guarantee that the output stays + * at its inactive state. However without the PWM disabled, the PWM + * driver refuses to suspend. So disable here even though this might + * enable the backlight on poorly designed boards. + */ + pwm_get_state(pb->pwm, &state); + state.duty_cycle = 0; + state.enabled = false; + pwm_apply_state(pb->pwm, &state); + if (pb->notify_after) pb->notify_after(pb->dev, 0);