hwmon: (pwm-fan) Fix suspend/resume behavior (48b9d5b4) · Commits · 戴 / test

The state of a PWM output is not clearly defined after resume. Some PWM drivers do not restore the duty cycle upon resume, thus it is necessary to manually restore the correct value. Signed-off-by:

Kamil Debski <k.debski@samsung.com> Signed-off-by:

Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/pwm-fan.c

+10 −3

Original line number	Diff line number	Diff line
		@@ -161,10 +161,17 @@ static int pwm_fan_suspend(struct device *dev)
		static int pwm_fan_resume(struct device *dev)
		{
		struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
		unsigned long duty;
		int ret;

		if (ctx->pwm_value)
		return pwm_enable(ctx->pwm);
		if (ctx->pwm_value == 0)
		return 0;

		duty = DIV_ROUND_UP(ctx->pwm_value * (ctx->pwm->period - 1), MAX_PWM);
		ret = pwm_config(ctx->pwm, duty, ctx->pwm->period);
		if (ret)
		return ret;
		return pwm_enable(ctx->pwm);
		}
		#endif

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