RE: [PATCHv6 1/4] pwm: Add Freescale FTM PWM driver support

From: Li.Xiubo@xxxxxxxxxxxxx
Date: Fri Dec 13 2013 - 04:32:29 EST



> > + struct fsl_pwm_chip *fpc;
> > +
> > + fpc = to_fsl_chip(chip);
> > +
> > + period_cycles = fsl_rate_to_cycles(fpc, period_ns);
> > + if (period_cycles > 0xFFFF) {
> > + dev_err(chip->dev, "required PWM period cycles(%lu) overflow "
> > + "16-bits counter!\n", period_cycles);
> > + return -EINVAL;
> > + }
> > +
> > + duty_cycles = fsl_rate_to_cycles(fpc, duty_ns);
> > + if (duty_cycles >= 0xFFFF) {
> > + dev_err(chip->dev, "required PWM duty cycles(%lu) overflow "
> > + "16-bits counter!\n", duty_cycles);
> > + return -EINVAL;
> > + }
>
> I'm not sure the error messages are all that useful. A -EINVAL error code
> should make it pretty clear what the problem is.
>

Yes, it is.

But for the pwm leds, there hasn't any check about the return values, if
there is something wrong, we cannot get any information about this.

So I think this error messages are useful for this case.


--
Xiubo
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