Re: [PATCH v3 6/6] hwmon: pwm-fan: Update the duty cycle inorder to control the pwm-fan

[Guenter Roeck <linux@roeck-us.net>]

On 04/12/2015 07:54 AM, Anand Moon wrote:
> In order to disable the PWM we need to update using following sequence.
>
> 	pwm_config(pwm, 0, period);
>   	pwm_disable(pwm);
>
> pwm_config() with a zero duty cycle to make it clear the timer and update the PWM registers.
> pwm_disable will clear the TCON_AUTORELOAD(tcon_chan) and update the PWM register.
>
There is no TCON_AUTORELOAD in this driver. Future developers will have no idea
what you are talking about here. Please provide a generic comment.

> Next change in state will get trigger unless a new PWM cycle happened.
>
That sentence is difficult to parse. Actually, I have no idea what it is supposed to mean.

> 	pwm_config(pwm, duty, period);
>   	pwm_enable(pwm);
>
> Through pwm_config we update the duty cycle and period and update the PWM register.
> pwm_enable will update the state to TCON_MANUALUPDATE(tcon_chan)
> and TCON_START(tcon_chan) | TCON_AUTORELOAD(tcon_chan) and update the PWM register.
>
This sentence does not make sense in the context of the pwm-fan driver.

> Reported-by: Markus Reichl <m.reichl@fivetechno.de>
> Tested-by: Markus Reichl <m.reichl@fivetechno.de>
> Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
> Reviewed-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
> Signed-off-by: Anand Moon <linux.amoon@gmail.com>
> ---
>   drivers/hwmon/pwm-fan.c | 10 ++++------
>   1 file changed, 4 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
> index 7c83dc4..f25c841 100644
> --- a/drivers/hwmon/pwm-fan.c
> +++ b/drivers/hwmon/pwm-fan.c
> @@ -44,26 +44,24 @@ static int  __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
>   	int ret = 0;
>
>   	mutex_lock(&ctx->lock);
> +

Please refrain from making unnecessary whitespace changes.

Thanks,
Guenter