Re: [rtc-linux] [PATCH v3 2/3] rtc: mediatek: Add MT6397 RTC driver

From: Joe Perches
Date: Tue May 05 2015 - 16:44:33 EST


On Tue, 2015-05-05 at 22:00 +0200, Alexandre Belloni wrote:
> Hi,
>
> This looks mostly good. Could you align the wrapped function parameters
> to the open parenthesis (use checkpatch --strict)?
>
> On 28/04/2015 at 15:35:55 +0800, Eddie Huang wrote :
> > +static int mtk_rtc_write_trigger(struct mt6397_rtc *rtc)
> > +{
> > + unsigned long timeout = jiffies + HZ;
> > + int ret;
> > + u32 data;
> > +
> > + ret = regmap_write(rtc->regmap, rtc->addr_base + RTC_WRTGR, 1);
> > + if (ret < 0)
> > + return ret;
> > +
> > + do {
> > + cpu_relax();
> > + ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_BBPU,
> > + &data);
> > + if (ret < 0)
> > + goto exit;
> > + } while ((data & RTC_BBPU_CBUSY) && time_after(timeout, jiffies));
> > +
>
> Shouldn't you return -ETIMEDOUT if the loop breaks because of time_after?

Probably yes.

I believe as written the time_after test is too much
for my little brain. I would have used time_before
and reversed the args.

I suggest moving the time_after() test into the loop,
use break; and remove the exit label too.

Maybe something like:

while (1) {
ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_BBPU,
&data);
if (ret < 0)
break;
if (!(data & RTC_BBPU_CBUSY))
break;
if (time_after(jiffies, timeout)) {
ret = -ETIMEDOUT;
break;
}
cpu_relax();
}

return ret;
}


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