Re: [PATCH v2 03/10] rtc: max77686: Use usleep_range() instead of msleep()

[Laxman Dewangan]

On Friday 22 January 2016 05:35 PM, Javier Martinez Canillas wrote:
> Hello Laxman,
>
> On 01/22/2016 06:41 AM, Laxman Dewangan wrote:
> > On Friday 22 January 2016 01:53 AM, Javier Martinez Canillas wrote:
> > >       RTC_SEC = 0,
> > > @@ -130,7 +130,8 @@ static int max77686_rtc_update(struct 
> > > max77686_rtc_info *info,
> > >                   __func__, ret, data);
> > >       else {
> > >           /* Minimum 16ms delay required before RTC update. */
> > > -        msleep(MAX77686_RTC_UPDATE_DELAY);
> > > +        usleep_range(MAX77686_RTC_UPDATE_DELAY,
> > > +                 MAX77686_RTC_UPDATE_DELAY * 2);
> > >       }
> >
> > Instead of making usleep_range(16000, 32000), can we make small range as
> > usleep_range(16000, 17000)?
>
> Yes, I also didn't know how to make the delay smaller. If I do for 
> example
>
> usleep_range(delay, delay + 10000), then the 10000 delta would be too big
> for max77802 (50 times the minimum required 200 delay).
>
> So I used delay * 2 for two reasons:
>
> 1) That way is generic enough and can work for any delay
>
> 2) My understanding is that most of times the delay should be precise and
>    is not that bad if sometimes the delay is the worst case (2 * X) since
>    after all the delay is the minimum required.
>
> I also see that usleep_range(X, X * 2) is a used pattern across the 
> kernel.

OK, fine to me here.

Acked-by: Laxman Dewangan <ldewangan@xxxxxxxxxx>