From 48b9d5b4f408259cd6800c4b17d4fe5025435da2 Mon Sep 17 00:00:00 2001 From: Kamil Debski Date: Mon, 3 Nov 2014 15:42:55 +0100 Subject: [PATCH] hwmon: (pwm-fan) Fix suspend/resume behavior 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 Signed-off-by: Guenter Roeck --- drivers/hwmon/pwm-fan.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c index 823c877a1ec0..1991d9032c38 100644 --- a/drivers/hwmon/pwm-fan.c +++ b/drivers/hwmon/pwm-fan.c @@ -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); - return 0; + 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 -- 2.30.2