Re: [PATCH v4] PWM: atmel-pwm: add PWM controller driver

[Bo Shen]

Hi Alexandre,

On 9/28/2013 00:52, Alexandre Belloni wrote:
[snip]

> > +static int atmel_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
> > +{
> > +	struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
> > +	int ret;
> > +
> > +	ret = clk_enable(atmel_pwm->clk);
> > +	if (ret) {
> > +		pr_err("failed to enable pwm clock\n");
> > +		return ret;
> > +	}
> > +
>
> This will increment clk->enable_count each time it is called.

Yes, that's true.

> > +	atmel_pwm_writel(atmel_pwm, PWM_ENA, 1 << pwm->hwpwm);
> > +
> > +	return 0;
> > +}
> > +
> > +static void atmel_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
> > +{
> > +	struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
> > +	u32 val;
> > +
> > +	atmel_pwm_writel(atmel_pwm, PWM_DIS, 1 << pwm->hwpwm);
> > +
> > +	val = atmel_pwm_readl(atmel_pwm, PWM_SR);
> > +	if ((val & PWM_SR_ALL_CH_ON) == 0)
> > +		clk_disable(atmel_pwm->clk);
> > +}
>
> This will decrement clk->enable_count only once there are no pwm enabled
> anymore.  So in you enable more than one channel, you will never disable
> the clock. The simple fix is to always call clk_diasble, regardless of
> the state of the other channels.

Thank for point out this.

I see you have sent out a patch to fix it (however the other contents of 
your patch doesn't work). So, do you prefer I send out v5 patch to fix 
this? or you fix your patch at same time fix this issue?

Best Regards,
Bo Shen
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