From 40da4737717b252fd01d92ff38d3b95a491167cc Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Mon, 9 Oct 2023 11:32:23 +0200 Subject: [PATCH] backlight: pwm_bl: Disable PWM on shutdown, suspend and remove MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Daniel Thompson Link: https://lore.kernel.org/r/20231009093223.227286-1-u.kleine-koenig@pengutronix.de Signed-off-by: Lee Jones --- drivers/video/backlight/pwm_bl.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) 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);