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backlight: pwm_bl: Disable PWM on shutdown, suspend and remove 

Since commit 00e7e698bf ("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: 00e7e698bf ("backlight: pwm_bl: Configure pwm only once per backlight toggle")
Reported-by: Aisheng Dong <aisheng.dong@nxp.com>
Tested-by: Aisheng Dong <aisheng.dong@nxp.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20231009093223.227286-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Lee Jones <lee@kernel.org>
This commit is contained in:
Uwe Kleine-König 2023-10-09 11:32:23 +02:00 committed by Lee Jones
parent 02c4e66165
commit 40da473771
1 changed files with 22 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
drivers/video/backlight/pwm_bl.c
View File

@ -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);