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leds: pwm: Disable PWM when going to suspend

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On stm32mp1xx based machines (and others) a PWM consumer has to disable
the PWM because an enabled PWM refuses to suspend. So check the
LED_SUSPENDED flag and depending on that set the .enabled property.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=218559
Fixes: 76fe464c8e ("leds: pwm: Don't disable the PWM when the LED should be off")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20240417153846.271751-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Lee Jones <lee@kernel.org>
This commit is contained in:
Uwe Kleine-König 2024-04-17 17:38:47 +02:00 committed by Lee Jones
parent aa172ba739
commit 974afccd37
1 changed files with 7 additions and 1 deletions
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8
drivers/leds/leds-pwm.c
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@ -53,7 +53,13 @@ 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 = true;
/*
* Disabling a PWM doesn't guarantee that it emits the inactive level.
* So keep it on. Only for suspending the PWM should be disabled because
* otherwise it refuses to suspend. The possible downside is that the
* LED might stay (or even go) on.
*/
led_dat->pwmstate.enabled = !(led_cdev->flags & LED_SUSPENDED);
return pwm_apply_might_sleep(led_dat->pwm, &led_dat->pwmstate);
}