Hi Sascha,
On Fri, 2015-03-13 at 11:57 +0100, Sascha Hauer wrote:
> Hi Eddie,
>
> On Fri, Mar 13, 2015 at 06:29:23PM +0800, Eddie Huang wrote:
> > > regmap_read() and regmap_write() can return errors. There is no
> > > checking for this.
> > >
> >
> > I encounter some trouble when I add code to check return value of
> > regmap_read and regmap_write. Every RTC register access through regmap,
> > and there are many register read/write in this driver. If I check every
> > return value, the driver will become ugly. I try to make this driver
> > clean using following macro.
> >
> > static int __rtc_read(struct mt6397_rtc *rtc, u32 offset, u32 *data)
> > {
> > u32 addr = rtc->addr_base + offset;
> >
> > if (offset < rtc->addr_range)
> > return regmap_read(rtc->regmap, addr, data);
> >
> > return -EINVAL;
> > }
> >
> > #define rtc_read(ret, rtc, offset, data) \
> > ({ \
> > ret = __rtc_read(rtc, offset, data); \
> > if (ret < 0) \
> > goto rtc_exit; \
> > }) \
>
> Hiding a goto (or return) in a macro is a very bad idea.
>
> what you can do is
>
> ret |= regmap_read(rtc->regmap, RTC_TC_SEC, &tm->tm_sec);
> ret |= regmap_read(rtc->regmap, RTC_TC_MIN, &tm->tm_min);
>
> if (ret)
> return -EIO;
>
> (Don't return ret in this case though as it might contain different
> error codes orred together)
>
OK, I will drop macro, and check regmap_read, regmap_write return value
in each function.
> Another possibilty at least for contiguous registers would be
> regmap_bulk_read().
>
> Sascha
>
Contiguous registers access occurs in reading and writing time. I think
Matthias's suggestion is a good way:
do {
ret = __mtk_rtc_read_time(rtc, &tm, &sec);
if (ret < 0)
goto rtc_exit;
} while (sec < tm->tm_sec);
Eddie
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