linux-kernel - RE: rtc: pcf85363/pcf85263: fix error that failed to run hwclock -w

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Date:   Fri, 16 Aug 2019 02:40:33 +0000
From:   Biwen Li <biwen.li@....com>
To:     Leo Li <leoyang.li@....com>,
        "a.zummo@...ertech.it" <a.zummo@...ertech.it>,
        "alexandre.belloni@...tlin.com" <alexandre.belloni@...tlin.com>
CC:     "linux-rtc@...r.kernel.org" <linux-rtc@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: rtc: pcf85363/pcf85263: fix error that failed to run hwclock -w

> > > > Subject: rtc: pcf85363/pcf85263: fix error that failed to run
> > > > hwclock -w
> > > >
> > > > Issue:
> > > >     # hwclock -w
> > > >     hwclock: RTC_SET_TIME: Invalid argument
> > > >
> > > > The patch fixes error when run command hwclock -w with rtc
> > > > pcf85363/pcf85263
> > >
> > > Can you explain a little bit more in the commit message on how the
> > changes fix
> > > the above issue?   It is not that clear just from the code.
> > 1. Relative patch: https://lkml.org/lkml/2019/4/3/55 , this patch will
> > always check for unwritable registers, it will compare reg with
> > max_register in regmap_writeable.
> >
> > 2. In drivers/rtc/rtc-pcf85363.c, CTRL_STOP_EN is 0x2e, but DT_100THS
> > is 0, max_regiter is 0x2f, then reg will be equal to 0x30, '0x30 <
> > 0x2f' is false,so regmap_writeable will return false.
> 
> From you description, it looks like the problem is actually that the buf[] was
> written to a wrong place.  If that's the case, we should say that in the commit
> message.
Yes, you are right, I will add this into commit message in v2. Thanks.
> 
> >
> > >
> > > >
> > > > Signed-off-by: Biwen Li <biwen.li@....com>
> > > > ---
> > > >  drivers/rtc/rtc-pcf85363.c | 7 ++++++-
> > > >  1 file changed, 6 insertions(+), 1 deletion(-)
> > > >
> > > > diff --git a/drivers/rtc/rtc-pcf85363.c
> > > > b/drivers/rtc/rtc-pcf85363.c index a075e77617dc..3450d615974d
> > > > 100644
> > > > --- a/drivers/rtc/rtc-pcf85363.c
> > > > +++ b/drivers/rtc/rtc-pcf85363.c
> > > > @@ -166,7 +166,12 @@ static int pcf85363_rtc_set_time(struct
> > > > device *dev, struct rtc_time *tm)
> > > >  	buf[DT_YEARS] = bin2bcd(tm->tm_year % 100);
> > > >
> > > >  	ret = regmap_bulk_write(pcf85363->regmap, CTRL_STOP_EN,
> > > > -				tmp, sizeof(tmp));
> > > > +				tmp, 2);
> > > > +	if (ret)
> > > > +		return ret;
> > > > +
> > > > +	ret = regmap_bulk_write(pcf85363->regmap, DT_100THS,
> > > > +				buf, sizeof(tmp) - 2);
> > > >  	if (ret)
> > > >  		return ret;
> > > >
> > > > --
> > > > 2.17.1